commit 0b055b3ad901863b6dbfd001f1b8f916b3cda023
Author: Adam Moussa <adam@seahavenind.com>
Date:   Sat May 16 18:40:46 2026 -0400

    Initial scaffold: monorepo structure, CDK stacks, CI/CD, domain model
    
    Phase 0 of proposal-system: complete project setup including:
    - CDK infrastructure (3 stacks: foundation, compute, frontend)
    - .NET 8 solution with Clean Architecture (Domain, Application, Infrastructure, Api)
    - EF Core data model (PostgreSQL) with all entities
    - Python Lambda placeholders (pdf-extract, pdf-generate, library-ingest)
    - React 19 web frontend scaffold (Vite + MUI)
    - React Native mobile placeholder
    - Shared TypeScript API contracts
    - GitHub Actions CI/CD (ci.yaml + deploy.yaml)
    - OIDC deploy role (githubdeploy-proposal-system)
    - Dependabot configuration
    - Cognito User Pool with Google OAuth, PKCE clients, groups

diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..8a4af3a
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,43 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: /infra
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 5
+
+  - package-ecosystem: npm
+    directory: /web
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 5
+
+  - package-ecosystem: nuget
+    directory: /api
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 5
+
+  - package-ecosystem: pip
+    directory: /lambdas/pdf-extract
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 3
+
+  - package-ecosystem: pip
+    directory: /lambdas/pdf-generate
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 3
+
+  - package-ecosystem: pip
+    directory: /lambdas/library-ingest
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 3
+
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 3
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
new file mode 100644
index 0000000..63a1e52
--- /dev/null
+++ b/.github/workflows/ci.yaml
@@ -0,0 +1,76 @@
+name: CI
+
+on:
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  dotnet:
+    name: .NET Build & Test
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: api
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '8.0.x'
+
+      - run: dotnet restore ProposalSystem.sln
+      - run: dotnet build ProposalSystem.sln --no-restore --configuration Release
+      - run: dotnet test ProposalSystem.sln --no-build --configuration Release
+
+  web:
+    name: Web Frontend Check
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: web
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: npm
+          cache-dependency-path: web/package-lock.json
+
+      - run: npm ci
+      - run: npx tsc --noEmit
+
+  python:
+    name: Python Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - run: pip install ruff
+      - run: ruff check lambdas/
+      - run: ruff format --check lambdas/
+
+  infra:
+    name: CDK Synth
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: infra
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: npm
+          cache-dependency-path: infra/package-lock.json
+
+      - run: npm ci
+      - run: npx cdk synth
diff --git a/.github/workflows/deploy.yaml b/.github/workflows/deploy.yaml
new file mode 100644
index 0000000..ddb2dd5
--- /dev/null
+++ b/.github/workflows/deploy.yaml
@@ -0,0 +1,89 @@
+name: Deploy
+
+on:
+  push:
+    branches: [main]
+
+permissions:
+  id-token: write
+  contents: read
+
+jobs:
+  deploy:
+    name: Deploy to AWS
+    runs-on: ubuntu-latest
+    environment: production
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: npm
+          cache-dependency-path: infra/package-lock.json
+
+      - uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '8.0.x'
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - uses: aws-actions/configure-aws-credentials@v4
+        with:
+          role-to-assume: ${{ secrets.AWS_DEPLOY_ROLE_ARN }}
+          aws-region: us-east-1
+
+      # Build .NET API
+      - name: Build API
+        working-directory: api
+        run: |
+          dotnet publish src/ProposalSystem.Api/ProposalSystem.Api.csproj \
+            --configuration Release \
+            --runtime linux-arm64 \
+            --self-contained false \
+            --output src/ProposalSystem.Api/bin/Release/net8.0/linux-arm64/publish
+
+      # Install Python dependencies for Lambdas
+      - name: Install PDF Extract deps
+        working-directory: lambdas/pdf-extract
+        run: pip install -r requirements.txt -t .
+
+      - name: Install PDF Generate deps
+        working-directory: lambdas/pdf-generate
+        run: pip install -r requirements.txt -t .
+
+      - name: Install Library Ingest deps
+        working-directory: lambdas/library-ingest
+        run: pip install -r requirements.txt -t .
+
+      # CDK Deploy
+      - name: CDK Deploy
+        working-directory: infra
+        run: |
+          npm ci
+          npx cdk deploy --all --require-approval never
+
+      # CloudFront Invalidation (after frontend deploy)
+      - name: Build Web Frontend
+        working-directory: web
+        run: |
+          npm ci
+          npm run build
+
+      - name: Deploy Web to S3
+        run: |
+          BUCKET=$(aws cloudformation describe-stacks \
+            --stack-name proposal-system-frontend \
+            --query "Stacks[0].Outputs[?OutputKey=='SiteBucketName'].OutputValue" \
+            --output text)
+          aws s3 sync web/dist "s3://$BUCKET" --delete
+
+      - name: Invalidate CloudFront
+        run: |
+          DIST_ID=$(aws cloudformation describe-stacks \
+            --stack-name proposal-system-frontend \
+            --query "Stacks[0].Outputs[?OutputKey=='DistributionId'].OutputValue" \
+            --output text)
+          aws cloudfront create-invalidation --distribution-id "$DIST_ID" --paths "/*"
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..45fc845
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,44 @@
+# .NET
+**/bin/Debug/
+**/bin/Release/
+**/obj/
+*.user
+*.suo
+*.vs/
+
+# Node
+node_modules/
+dist/
+.vite/
+
+# Python
+__pycache__/
+*.pyc
+.venv/
+venv/
+
+# CDK
+cdk.out/
+
+# SAM
+.aws-sam/
+
+# Environment
+.env
+.env.*
+!.env.example
+
+# IDE
+.idea/
+*.swp
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Test
+coverage/
+TestResults/
+
+# Build artifacts
+*.zip
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..65bde41
--- /dev/null
+++ b/README.md
@@ -0,0 +1,100 @@
+# Proposal Management System
+
+AI-powered proposal generation and management system for Sea Haven Industries. Enables dispatchers to submit proposal requests, uses Bedrock RAG to auto-generate draft line items from historical data, and provides admins with a pricing/approval workspace with professional PDF output.
+
+## Architecture
+
+| Layer | Technology |
+|---|---|
+| Backend API | .NET 8 / ASP.NET Core on Lambda (`Amazon.Lambda.AspNetCoreServer`) |
+| Database | RDS PostgreSQL 15 + EF Core |
+| Frontend Web | React 19 + MUI v7 + TypeScript |
+| Mobile | React Native (iOS-first) |
+| IaC | CDK (TypeScript) - 3 stacks |
+| AI/RAG | Bedrock Knowledge Base + Claude (Bedrock Runtime) |
+| PDF Processing | Python 3.12 Lambdas |
+| Auth | Cognito User Pool + Google OAuth |
+| Storage | S3 (PDFs, attachments, library) |
+| Notifications | Slack Bot API |
+
+## AWS Resources
+
+- **Stack prefix:** `proposal-system-*`
+- **Account:** 328440206208
+- **Region:** us-east-1
+
+| Resource | Name |
+|---|---|
+| Lambda (.NET 8) | `proposal-system-api` |
+| API Gateway HTTP API | `proposal-system-gateway` |
+| RDS PostgreSQL | `proposal-system-db` |
+| S3 Buckets | `proposal-system-uploads`, `proposal-system-generated`, `proposal-system-library` |
+| Bedrock Knowledge Base | `proposal-system-kb` |
+| Lambda (Python) | `proposal-system-pdf-extract`, `proposal-system-pdf-generate`, `proposal-system-library-ingest` |
+| Cognito User Pool | `proposal-system-auth` |
+| CloudFront | `proposal-system-web` |
+| SQS Queue | `proposal-system-jobs` + DLQ |
+
+## Repository Structure
+
+```
+proposal-system/
+├── infra/          # CDK app (TypeScript) - 3 stacks
+├── api/            # .NET 8 Web API (Lambda-hosted)
+├── web/            # React 19 + MUI frontend
+├── mobile/         # React Native app (iOS)
+├── lambdas/        # Python 3.12 processing functions
+├── shared/         # Shared TypeScript types/contracts
+└── .github/        # CI/CD workflows
+```
+
+## Local Development
+
+### Prerequisites
+
+- .NET 8 SDK
+- Node.js 24
+- Python 3.12
+- AWS CDK CLI (`npm install -g aws-cdk@2.253.1`)
+
+### Backend API
+
+```bash
+cd api
+dotnet restore
+dotnet run --project src/ProposalSystem.Api
+```
+
+### Web Frontend
+
+```bash
+cd web
+npm install
+npm run dev
+```
+
+### Infrastructure
+
+```bash
+cd infra
+npm install
+npx cdk synth
+npx cdk deploy --all
+```
+
+## CI/CD
+
+- **CI:** Runs on pull requests to `main` (dotnet build/test, tsc, ruff, cdk synth)
+- **Deploy:** Runs on push to `main` (cdk deploy, frontend S3 sync, CloudFront invalidation)
+- **OIDC Role:** `githubdeploy-proposal-system`
+
+## Data Flow
+
+1. Dispatcher submits proposal request (web or mobile)
+2. API creates proposal record, publishes SQS message
+3. If vendor PDF attached: `pdf-extract` Lambda parses and structures data
+4. Suggestion engine queries Bedrock KB for similar proposals, generates line items via Claude
+5. Admin reviews/edits line items in workspace
+6. On approval: `pdf-generate` Lambda creates branded PDF
+7. On send: `library-ingest` Lambda adds to KB for future matching
+8. Slack notifications at key status transitions
diff --git a/api/ProposalSystem.sln b/api/ProposalSystem.sln
new file mode 100644
index 0000000..f34f266
--- /dev/null
+++ b/api/ProposalSystem.sln
@@ -0,0 +1,37 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31903.59
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProposalSystem.Api", "src\ProposalSystem.Api\ProposalSystem.Api.csproj", "{A1B2C3D4-1111-2222-3333-444455556666}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProposalSystem.Domain", "src\ProposalSystem.Domain\ProposalSystem.Domain.csproj", "{A1B2C3D4-1111-2222-3333-444455557777}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProposalSystem.Application", "src\ProposalSystem.Application\ProposalSystem.Application.csproj", "{A1B2C3D4-1111-2222-3333-444455558888}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProposalSystem.Infrastructure", "src\ProposalSystem.Infrastructure\ProposalSystem.Infrastructure.csproj", "{A1B2C3D4-1111-2222-3333-444455559999}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{A1B2C3D4-1111-2222-3333-444455556666}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455556666}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455556666}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455556666}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455557777}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455557777}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455557777}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455557777}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455558888}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455558888}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455558888}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455558888}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455559999}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455559999}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455559999}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A1B2C3D4-1111-2222-3333-444455559999}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal
diff --git a/api/global.json b/api/global.json
new file mode 100644
index 0000000..ae9f38c
--- /dev/null
+++ b/api/global.json
@@ -0,0 +1,6 @@
+{
+  "sdk": {
+    "version": "8.0.400",
+    "rollForward": "latestFeature"
+  }
+}
diff --git a/api/src/ProposalSystem.Api/Controllers/HealthController.cs b/api/src/ProposalSystem.Api/Controllers/HealthController.cs
new file mode 100644
index 0000000..e631afc
--- /dev/null
+++ b/api/src/ProposalSystem.Api/Controllers/HealthController.cs
@@ -0,0 +1,11 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace ProposalSystem.Api.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class HealthController : ControllerBase
+{
+    [HttpGet]
+    public IActionResult Get() => Ok(new { status = "healthy", timestamp = DateTime.UtcNow });
+}
diff --git a/api/src/ProposalSystem.Api/Program.cs b/api/src/ProposalSystem.Api/Program.cs
new file mode 100644
index 0000000..a6f7942
--- /dev/null
+++ b/api/src/ProposalSystem.Api/Program.cs
@@ -0,0 +1,32 @@
+using Microsoft.EntityFrameworkCore;
+using ProposalSystem.Infrastructure.Data;
+
+var builder = WebApplication.CreateBuilder(args);
+
+builder.Services.AddControllers();
+builder.Services.AddEndpointsApiExplorer();
+
+builder.Services.AddDbContext<ProposalDbContext>(options =>
+    options.UseNpgsql(builder.Configuration.GetConnectionString("DefaultConnection")));
+
+builder.Services.AddAuthentication("Bearer")
+    .AddJwtBearer(options =>
+    {
+        options.Authority = builder.Configuration["Auth:Authority"];
+        options.Audience = builder.Configuration["Auth:Audience"];
+    });
+
+builder.Services.AddAuthorization();
+builder.Services.AddHealthChecks()
+    .AddDbContextCheck<ProposalDbContext>();
+
+builder.Services.AddAWSLambdaHosting(LambdaEventSource.HttpApi);
+
+var app = builder.Build();
+
+app.UseAuthentication();
+app.UseAuthorization();
+app.MapControllers();
+app.MapHealthChecks("/api/health");
+
+app.Run();
diff --git a/api/src/ProposalSystem.Api/ProposalSystem.Api.csproj b/api/src/ProposalSystem.Api/ProposalSystem.Api.csproj
new file mode 100644
index 0000000..17e9175
--- /dev/null
+++ b/api/src/ProposalSystem.Api/ProposalSystem.Api.csproj
@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
+    <AWSProjectType>Lambda</AWSProjectType>
+    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+    <PublishReadyToRun>true</PublishReadyToRun>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ProposalSystem.Application\ProposalSystem.Application.csproj" />
+    <ProjectReference Include="..\ProposalSystem.Infrastructure\ProposalSystem.Infrastructure.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Amazon.Lambda.AspNetCoreServer.Hosting" Version="1.7.2" />
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="8.0.11" />
+    <PackageReference Include="FluentValidation.AspNetCore" Version="11.3.0" />
+  </ItemGroup>
+
+</Project>
diff --git a/api/src/ProposalSystem.Api/appsettings.json b/api/src/ProposalSystem.Api/appsettings.json
new file mode 100644
index 0000000..38ef245
--- /dev/null
+++ b/api/src/ProposalSystem.Api/appsettings.json
@@ -0,0 +1,15 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "Auth": {
+    "Authority": "",
+    "Audience": ""
+  },
+  "ConnectionStrings": {
+    "DefaultConnection": ""
+  }
+}
diff --git a/api/src/ProposalSystem.Application/Interfaces/IProposalRepository.cs b/api/src/ProposalSystem.Application/Interfaces/IProposalRepository.cs
new file mode 100644
index 0000000..8465b74
--- /dev/null
+++ b/api/src/ProposalSystem.Application/Interfaces/IProposalRepository.cs
@@ -0,0 +1,11 @@
+using ProposalSystem.Domain.Entities;
+
+namespace ProposalSystem.Application.Interfaces;
+
+public interface IProposalRepository
+{
+    Task<Proposal?> GetByIdAsync(Guid id, CancellationToken ct = default);
+    Task<IReadOnlyList<Proposal>> GetAllAsync(CancellationToken ct = default);
+    Task<Proposal> CreateAsync(Proposal proposal, CancellationToken ct = default);
+    Task UpdateAsync(Proposal proposal, CancellationToken ct = default);
+}
diff --git a/api/src/ProposalSystem.Application/ProposalSystem.Application.csproj b/api/src/ProposalSystem.Application/ProposalSystem.Application.csproj
new file mode 100644
index 0000000..592a41b
--- /dev/null
+++ b/api/src/ProposalSystem.Application/ProposalSystem.Application.csproj
@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ProposalSystem.Domain\ProposalSystem.Domain.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="FluentValidation" Version="11.11.0" />
+  </ItemGroup>
+
+</Project>
diff --git a/api/src/ProposalSystem.Domain/Entities/AuditLog.cs b/api/src/ProposalSystem.Domain/Entities/AuditLog.cs
new file mode 100644
index 0000000..c5d9e0e
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/Entities/AuditLog.cs
@@ -0,0 +1,32 @@
+namespace ProposalSystem.Domain.Entities;
+
+public enum AuditAction
+{
+    Submit,
+    Edit,
+    Approve,
+    Download,
+    Regenerate,
+    Revise,
+    AssignAdmin,
+    EditLineItem,
+    EditScope,
+    GeneratePDF,
+    MarkSent,
+    CreateRevision,
+    UpdateRole
+}
+
+public class AuditLog
+{
+    public Guid Id { get; set; }
+    public Guid? ProposalId { get; set; }
+    public Guid UserId { get; set; }
+    public AuditAction Action { get; set; }
+    public string? Details { get; set; }
+    public DateTime Timestamp { get; set; }
+    public string? IpAddress { get; set; }
+
+    public Proposal? Proposal { get; set; }
+    public User? User { get; set; }
+}
diff --git a/api/src/ProposalSystem.Domain/Entities/Customer.cs b/api/src/ProposalSystem.Domain/Entities/Customer.cs
new file mode 100644
index 0000000..468145d
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/Entities/Customer.cs
@@ -0,0 +1,10 @@
+namespace ProposalSystem.Domain.Entities;
+
+public class Customer
+{
+    public Guid Id { get; set; }
+    public string Name { get; set; } = string.Empty;
+    public string? Addresses { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime UpdatedAt { get; set; }
+}
diff --git a/api/src/ProposalSystem.Domain/Entities/GeneratedPdf.cs b/api/src/ProposalSystem.Domain/Entities/GeneratedPdf.cs
new file mode 100644
index 0000000..f58377e
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/Entities/GeneratedPdf.cs
@@ -0,0 +1,14 @@
+namespace ProposalSystem.Domain.Entities;
+
+public class GeneratedPdf
+{
+    public Guid Id { get; set; }
+    public Guid ProposalId { get; set; }
+    public int Revision { get; set; }
+    public string S3Key { get; set; } = string.Empty;
+    public DateTime GeneratedAt { get; set; }
+    public Guid GeneratedById { get; set; }
+
+    public Proposal? Proposal { get; set; }
+    public User? GeneratedBy { get; set; }
+}
diff --git a/api/src/ProposalSystem.Domain/Entities/LineItem.cs b/api/src/ProposalSystem.Domain/Entities/LineItem.cs
new file mode 100644
index 0000000..e876e18
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/Entities/LineItem.cs
@@ -0,0 +1,34 @@
+namespace ProposalSystem.Domain.Entities;
+
+public enum PricingMode
+{
+    UnitPrice,
+    TotalPrice,
+    Both
+}
+
+public enum LineItemSource
+{
+    AI,
+    Vendor,
+    Manual,
+    Historical
+}
+
+public class LineItem
+{
+    public Guid Id { get; set; }
+    public Guid ProposalId { get; set; }
+    public string Description { get; set; } = string.Empty;
+    public decimal Quantity { get; set; }
+    public string Unit { get; set; } = string.Empty;
+    public decimal? UnitPrice { get; set; }
+    public decimal TotalPrice { get; set; }
+    public PricingMode PricingMode { get; set; }
+    public int SortOrder { get; set; }
+    public LineItemSource Source { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime UpdatedAt { get; set; }
+
+    public Proposal? Proposal { get; set; }
+}
diff --git a/api/src/ProposalSystem.Domain/Entities/Proposal.cs b/api/src/ProposalSystem.Domain/Entities/Proposal.cs
new file mode 100644
index 0000000..9674287
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/Entities/Proposal.cs
@@ -0,0 +1,60 @@
+namespace ProposalSystem.Domain.Entities;
+
+public enum ProposalStatus
+{
+    Draft,
+    InReview,
+    Approved,
+    Sent,
+    Revised
+}
+
+public enum ServiceCategory
+{
+    HVAC,
+    Plumbing,
+    Electrical,
+    General,
+    Renovation
+}
+
+public enum Priority
+{
+    Standard,
+    Urgent,
+    Emergency
+}
+
+public class Proposal
+{
+    public Guid Id { get; set; }
+    public string ProposalNumber { get; set; } = string.Empty;
+    public string WorkOrderNumber { get; set; } = string.Empty;
+    public string CustomerName { get; set; } = string.Empty;
+    public string CustomerAddress { get; set; } = string.Empty;
+    public string ScopeOfWork { get; set; } = string.Empty;
+    public string? RefinedScope { get; set; }
+    public ServiceCategory ServiceCategory { get; set; }
+    public Priority Priority { get; set; }
+    public ProposalStatus Status { get; set; }
+    public decimal TotalBidAmount { get; set; }
+    public decimal? VendorTotalCost { get; set; }
+    public string Notes { get; set; } = string.Empty;
+    public Guid SubmittedById { get; set; }
+    public DateTime SubmittedAt { get; set; }
+    public Guid? AssignedAdminId { get; set; }
+    public Guid? ApprovedById { get; set; }
+    public DateTime? ApprovedAt { get; set; }
+    public DateTime? SentAt { get; set; }
+    public int CurrentRevision { get; set; } = 1;
+    public Guid? ParentProposalId { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime UpdatedAt { get; set; }
+
+    public User? SubmittedBy { get; set; }
+    public User? AssignedAdmin { get; set; }
+    public User? ApprovedBy { get; set; }
+    public Proposal? ParentProposal { get; set; }
+    public ICollection<LineItem> LineItems { get; set; } = new List<LineItem>();
+    public ICollection<VendorProposal> VendorProposals { get; set; } = new List<VendorProposal>();
+}
diff --git a/api/src/ProposalSystem.Domain/Entities/SimilarProposalReference.cs b/api/src/ProposalSystem.Domain/Entities/SimilarProposalReference.cs
new file mode 100644
index 0000000..773c3f8
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/Entities/SimilarProposalReference.cs
@@ -0,0 +1,14 @@
+namespace ProposalSystem.Domain.Entities;
+
+public class SimilarProposalReference
+{
+    public Guid Id { get; set; }
+    public Guid ProposalId { get; set; }
+    public string ReferencedLibraryItemId { get; set; } = string.Empty;
+    public float SimilarityScore { get; set; }
+    public DateTime ReferencedAt { get; set; }
+    public Guid ReferencedById { get; set; }
+
+    public Proposal? Proposal { get; set; }
+    public User? ReferencedBy { get; set; }
+}
diff --git a/api/src/ProposalSystem.Domain/Entities/User.cs b/api/src/ProposalSystem.Domain/Entities/User.cs
new file mode 100644
index 0000000..d808ae5
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/Entities/User.cs
@@ -0,0 +1,20 @@
+namespace ProposalSystem.Domain.Entities;
+
+public enum UserRole
+{
+    Dispatcher,
+    Admin,
+    SysAdmin
+}
+
+public class User
+{
+    public Guid Id { get; set; }
+    public string CognitoSub { get; set; } = string.Empty;
+    public string Email { get; set; } = string.Empty;
+    public string DisplayName { get; set; } = string.Empty;
+    public UserRole Role { get; set; }
+    public bool IsActive { get; set; } = true;
+    public DateTime CreatedAt { get; set; }
+    public DateTime UpdatedAt { get; set; }
+}
diff --git a/api/src/ProposalSystem.Domain/Entities/VendorProposal.cs b/api/src/ProposalSystem.Domain/Entities/VendorProposal.cs
new file mode 100644
index 0000000..f59a7b6
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/Entities/VendorProposal.cs
@@ -0,0 +1,24 @@
+namespace ProposalSystem.Domain.Entities;
+
+public enum ProcessingStatus
+{
+    Pending,
+    Processing,
+    Complete,
+    Failed
+}
+
+public class VendorProposal
+{
+    public Guid Id { get; set; }
+    public Guid ProposalId { get; set; }
+    public string VendorName { get; set; } = string.Empty;
+    public string FileName { get; set; } = string.Empty;
+    public string S3Key { get; set; } = string.Empty;
+    public string? ExtractedData { get; set; }
+    public decimal TotalVendorCost { get; set; }
+    public DateTime UploadedAt { get; set; }
+    public ProcessingStatus ProcessingStatus { get; set; }
+
+    public Proposal? Proposal { get; set; }
+}
diff --git a/api/src/ProposalSystem.Domain/ProposalSystem.Domain.csproj b/api/src/ProposalSystem.Domain/ProposalSystem.Domain.csproj
new file mode 100644
index 0000000..5d6e827
--- /dev/null
+++ b/api/src/ProposalSystem.Domain/ProposalSystem.Domain.csproj
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+</Project>
diff --git a/api/src/ProposalSystem.Infrastructure/Data/ProposalDbContext.cs b/api/src/ProposalSystem.Infrastructure/Data/ProposalDbContext.cs
new file mode 100644
index 0000000..70b882e
--- /dev/null
+++ b/api/src/ProposalSystem.Infrastructure/Data/ProposalDbContext.cs
@@ -0,0 +1,96 @@
+using Microsoft.EntityFrameworkCore;
+using ProposalSystem.Domain.Entities;
+
+namespace ProposalSystem.Infrastructure.Data;
+
+public class ProposalDbContext : DbContext
+{
+    public ProposalDbContext(DbContextOptions<ProposalDbContext> options) : base(options)
+    {
+    }
+
+    public DbSet<Proposal> Proposals => Set<Proposal>();
+    public DbSet<LineItem> LineItems => Set<LineItem>();
+    public DbSet<VendorProposal> VendorProposals => Set<VendorProposal>();
+    public DbSet<Customer> Customers => Set<Customer>();
+    public DbSet<User> Users => Set<User>();
+    public DbSet<AuditLog> AuditLogs => Set<AuditLog>();
+    public DbSet<SimilarProposalReference> SimilarProposalReferences => Set<SimilarProposalReference>();
+    public DbSet<GeneratedPdf> GeneratedPdfs => Set<GeneratedPdf>();
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        modelBuilder.Entity<Proposal>(entity =>
+        {
+            entity.HasKey(e => e.Id);
+            entity.HasIndex(e => e.ProposalNumber).IsUnique();
+            entity.Property(e => e.TotalBidAmount).HasPrecision(18, 2);
+            entity.Property(e => e.VendorTotalCost).HasPrecision(18, 2);
+            entity.Property(e => e.Status).HasConversion<string>();
+            entity.Property(e => e.ServiceCategory).HasConversion<string>();
+            entity.Property(e => e.Priority).HasConversion<string>();
+
+            entity.HasOne(e => e.SubmittedBy).WithMany().HasForeignKey(e => e.SubmittedById).OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(e => e.AssignedAdmin).WithMany().HasForeignKey(e => e.AssignedAdminId).OnDelete(DeleteBehavior.SetNull);
+            entity.HasOne(e => e.ApprovedBy).WithMany().HasForeignKey(e => e.ApprovedById).OnDelete(DeleteBehavior.SetNull);
+            entity.HasOne(e => e.ParentProposal).WithMany().HasForeignKey(e => e.ParentProposalId).OnDelete(DeleteBehavior.SetNull);
+        });
+
+        modelBuilder.Entity<LineItem>(entity =>
+        {
+            entity.HasKey(e => e.Id);
+            entity.Property(e => e.Quantity).HasPrecision(18, 4);
+            entity.Property(e => e.UnitPrice).HasPrecision(18, 2);
+            entity.Property(e => e.TotalPrice).HasPrecision(18, 2);
+            entity.Property(e => e.PricingMode).HasConversion<string>();
+            entity.Property(e => e.Source).HasConversion<string>();
+
+            entity.HasOne(e => e.Proposal).WithMany(p => p.LineItems).HasForeignKey(e => e.ProposalId).OnDelete(DeleteBehavior.Cascade);
+        });
+
+        modelBuilder.Entity<VendorProposal>(entity =>
+        {
+            entity.HasKey(e => e.Id);
+            entity.Property(e => e.TotalVendorCost).HasPrecision(18, 2);
+            entity.Property(e => e.ProcessingStatus).HasConversion<string>();
+            entity.Property(e => e.ExtractedData).HasColumnType("jsonb");
+
+            entity.HasOne(e => e.Proposal).WithMany(p => p.VendorProposals).HasForeignKey(e => e.ProposalId).OnDelete(DeleteBehavior.Cascade);
+        });
+
+        modelBuilder.Entity<Customer>(entity =>
+        {
+            entity.HasKey(e => e.Id);
+            entity.Property(e => e.Addresses).HasColumnType("jsonb");
+        });
+
+        modelBuilder.Entity<User>(entity =>
+        {
+            entity.HasKey(e => e.Id);
+            entity.HasIndex(e => e.CognitoSub).IsUnique();
+            entity.HasIndex(e => e.Email).IsUnique();
+            entity.Property(e => e.Role).HasConversion<string>();
+        });
+
+        modelBuilder.Entity<AuditLog>(entity =>
+        {
+            entity.HasKey(e => e.Id);
+            entity.Property(e => e.Action).HasConversion<string>();
+            entity.Property(e => e.Details).HasColumnType("jsonb");
+            entity.HasIndex(e => e.ProposalId);
+            entity.HasIndex(e => e.Timestamp);
+        });
+
+        modelBuilder.Entity<SimilarProposalReference>(entity =>
+        {
+            entity.HasKey(e => e.Id);
+            entity.HasOne(e => e.Proposal).WithMany().HasForeignKey(e => e.ProposalId).OnDelete(DeleteBehavior.Cascade);
+        });
+
+        modelBuilder.Entity<GeneratedPdf>(entity =>
+        {
+            entity.HasKey(e => e.Id);
+            entity.HasOne(e => e.Proposal).WithMany().HasForeignKey(e => e.ProposalId).OnDelete(DeleteBehavior.Cascade);
+        });
+    }
+}
diff --git a/api/src/ProposalSystem.Infrastructure/ProposalSystem.Infrastructure.csproj b/api/src/ProposalSystem.Infrastructure/ProposalSystem.Infrastructure.csproj
new file mode 100644
index 0000000..5b7e787
--- /dev/null
+++ b/api/src/ProposalSystem.Infrastructure/ProposalSystem.Infrastructure.csproj
@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ProposalSystem.Application\ProposalSystem.Application.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="8.0.11" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.11" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="8.0.11" />
+    <PackageReference Include="AWSSDK.S3" Version="3.7.405.0" />
+    <PackageReference Include="AWSSDK.SQS" Version="3.7.401.0" />
+    <PackageReference Include="AWSSDK.SecretsManager" Version="3.7.401.0" />
+  </ItemGroup>
+
+</Project>
diff --git a/infra/bin/app.ts b/infra/bin/app.ts
new file mode 100644
index 0000000..759b825
--- /dev/null
+++ b/infra/bin/app.ts
@@ -0,0 +1,37 @@
+import * as cdk from 'aws-cdk-lib';
+import { FoundationStack } from '../lib/foundation-stack';
+import { ComputeStack } from '../lib/compute-stack';
+import { FrontendStack } from '../lib/frontend-stack';
+
+const app = new cdk.App();
+
+const env: cdk.Environment = {
+  account: '328440206208',
+  region: 'us-east-1',
+};
+
+const foundation = new FoundationStack(app, 'proposal-system-foundation', {
+  stackName: 'proposal-system-foundation',
+  env,
+  description: 'Proposal System - VPC, RDS, S3, SQS, Cognito',
+});
+
+const compute = new ComputeStack(app, 'proposal-system-compute', {
+  stackName: 'proposal-system-compute',
+  env,
+  description: 'Proposal System - API Lambda, Python Lambdas, Bedrock KB',
+  vpc: foundation.vpc,
+  lambdaSecurityGroup: foundation.lambdaSecurityGroup,
+  dbSecret: foundation.dbSecret,
+  uploadsBucket: foundation.uploadsBucket,
+  generatedBucket: foundation.generatedBucket,
+  libraryBucket: foundation.libraryBucket,
+  jobsQueue: foundation.jobsQueue,
+  userPool: foundation.userPool,
+});
+
+new FrontendStack(app, 'proposal-system-frontend', {
+  stackName: 'proposal-system-frontend',
+  env,
+  description: 'Proposal System - CloudFront + S3 web hosting',
+});
diff --git a/infra/cdk.context.json b/infra/cdk.context.json
new file mode 100644
index 0000000..2145e1d
--- /dev/null
+++ b/infra/cdk.context.json
@@ -0,0 +1,10 @@
+{
+  "availability-zones:account=328440206208:region=us-east-1": [
+    "us-east-1a",
+    "us-east-1b",
+    "us-east-1c",
+    "us-east-1d",
+    "us-east-1e",
+    "us-east-1f"
+  ]
+}
diff --git a/infra/cdk.json b/infra/cdk.json
new file mode 100644
index 0000000..72066ba
--- /dev/null
+++ b/infra/cdk.json
@@ -0,0 +1,21 @@
+{
+  "app": "npx ts-node --prefer-ts-exts bin/app.ts",
+  "watch": {
+    "include": ["**"],
+    "exclude": [
+      "README.md",
+      "cdk*.json",
+      "**/*.d.ts",
+      "**/*.js",
+      "tsconfig.json",
+      "package*.json",
+      "node_modules",
+      "dist"
+    ]
+  },
+  "context": {
+    "@aws-cdk/aws-lambda:recognizeLayerVersion": true,
+    "@aws-cdk/core:checkSecretUsage": true,
+    "@aws-cdk/core:target-partitions": ["aws"]
+  }
+}
diff --git a/infra/lib/compute-stack.ts b/infra/lib/compute-stack.ts
new file mode 100644
index 0000000..c5e0553
--- /dev/null
+++ b/infra/lib/compute-stack.ts
@@ -0,0 +1,199 @@
+import * as cdk from 'aws-cdk-lib';
+import * as ec2 from 'aws-cdk-lib/aws-ec2';
+import * as lambda from 'aws-cdk-lib/aws-lambda';
+import * as apigatewayv2 from 'aws-cdk-lib/aws-apigatewayv2';
+import * as apigatewayv2Integrations from 'aws-cdk-lib/aws-apigatewayv2-integrations';
+import * as iam from 'aws-cdk-lib/aws-iam';
+import * as s3 from 'aws-cdk-lib/aws-s3';
+import * as sqs from 'aws-cdk-lib/aws-sqs';
+import * as cognito from 'aws-cdk-lib/aws-cognito';
+import * as secretsmanager from 'aws-cdk-lib/aws-secretsmanager';
+import * as lambdaEventSources from 'aws-cdk-lib/aws-lambda-event-sources';
+import { Construct } from 'constructs';
+
+export interface ComputeStackProps extends cdk.StackProps {
+  vpc: ec2.IVpc;
+  lambdaSecurityGroup: ec2.ISecurityGroup;
+  dbSecret: secretsmanager.ISecret;
+  uploadsBucket: s3.IBucket;
+  generatedBucket: s3.IBucket;
+  libraryBucket: s3.IBucket;
+  jobsQueue: sqs.IQueue;
+  userPool: cognito.IUserPool;
+}
+
+export class ComputeStack extends cdk.Stack {
+  constructor(scope: Construct, id: string, props: ComputeStackProps) {
+    super(scope, id, props);
+
+    const privateSubnets = { subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS };
+
+    // .NET 8 API Lambda
+    const apiFunction = new lambda.Function(this, 'ApiFunction', {
+      functionName: 'proposal-system-api',
+      runtime: lambda.Runtime.DOTNET_8,
+      architecture: lambda.Architecture.ARM_64,
+      handler: 'ProposalSystem.Api',
+      code: lambda.Code.fromAsset('../api/src/ProposalSystem.Api/bin/Release/net8.0/linux-arm64/publish'),
+      memorySize: 1024,
+      timeout: cdk.Duration.seconds(30),
+      vpc: props.vpc,
+      vpcSubnets: privateSubnets,
+      securityGroups: [props.lambdaSecurityGroup],
+      environment: {
+        ASPNETCORE_ENVIRONMENT: 'Production',
+        DB_SECRET_ARN: props.dbSecret.secretArn,
+        UPLOADS_BUCKET: props.uploadsBucket.bucketName,
+        GENERATED_BUCKET: props.generatedBucket.bucketName,
+        LIBRARY_BUCKET: props.libraryBucket.bucketName,
+        JOBS_QUEUE_URL: props.jobsQueue.queueUrl,
+      },
+      tracing: lambda.Tracing.ACTIVE,
+    });
+
+    // API Lambda permissions
+    props.dbSecret.grantRead(apiFunction);
+    props.uploadsBucket.grantReadWrite(apiFunction);
+    props.generatedBucket.grantRead(apiFunction);
+    props.jobsQueue.grantSendMessages(apiFunction);
+
+    apiFunction.addToRolePolicy(new iam.PolicyStatement({
+      actions: ['cognito-idp:AdminGetUser', 'cognito-idp:AdminListGroupsForUser'],
+      resources: [props.userPool.userPoolArn],
+    }));
+
+    // API Gateway HTTP API
+    const httpApi = new apigatewayv2.HttpApi(this, 'HttpApi', {
+      apiName: 'proposal-system-gateway',
+      corsPreflight: {
+        allowOrigins: [
+          'https://proposals.seahaven.com',
+          'http://localhost:5173',
+        ],
+        allowMethods: [
+          apigatewayv2.CorsHttpMethod.GET,
+          apigatewayv2.CorsHttpMethod.POST,
+          apigatewayv2.CorsHttpMethod.PUT,
+          apigatewayv2.CorsHttpMethod.DELETE,
+          apigatewayv2.CorsHttpMethod.OPTIONS,
+        ],
+        allowHeaders: ['Authorization', 'Content-Type', 'X-Requested-With'],
+        maxAge: cdk.Duration.hours(1),
+      },
+    });
+
+    const apiIntegration = new apigatewayv2Integrations.HttpLambdaIntegration(
+      'ApiIntegration',
+      apiFunction
+    );
+
+    httpApi.addRoutes({
+      path: '/{proxy+}',
+      methods: [apigatewayv2.HttpMethod.ANY],
+      integration: apiIntegration,
+    });
+
+    // Python Lambda: PDF Extract
+    const pdfExtractFunction = new lambda.Function(this, 'PdfExtractFunction', {
+      functionName: 'proposal-system-pdf-extract',
+      runtime: lambda.Runtime.PYTHON_3_12,
+      architecture: lambda.Architecture.ARM_64,
+      handler: 'app.handler',
+      code: lambda.Code.fromAsset('../lambdas/pdf-extract'),
+      memorySize: 1024,
+      timeout: cdk.Duration.seconds(120),
+      vpc: props.vpc,
+      vpcSubnets: privateSubnets,
+      securityGroups: [props.lambdaSecurityGroup],
+      environment: {
+        UPLOADS_BUCKET: props.uploadsBucket.bucketName,
+        API_BASE_URL: httpApi.apiEndpoint,
+      },
+    });
+
+    props.uploadsBucket.grantRead(pdfExtractFunction);
+    pdfExtractFunction.addToRolePolicy(new iam.PolicyStatement({
+      actions: ['bedrock:InvokeModel'],
+      resources: ['*'],
+    }));
+
+    // Python Lambda: PDF Generate
+    const pdfGenerateFunction = new lambda.Function(this, 'PdfGenerateFunction', {
+      functionName: 'proposal-system-pdf-generate',
+      runtime: lambda.Runtime.PYTHON_3_12,
+      architecture: lambda.Architecture.ARM_64,
+      handler: 'app.handler',
+      code: lambda.Code.fromAsset('../lambdas/pdf-generate'),
+      memorySize: 512,
+      timeout: cdk.Duration.seconds(30),
+      vpc: props.vpc,
+      vpcSubnets: privateSubnets,
+      securityGroups: [props.lambdaSecurityGroup],
+      environment: {
+        GENERATED_BUCKET: props.generatedBucket.bucketName,
+        API_BASE_URL: httpApi.apiEndpoint,
+      },
+    });
+
+    props.generatedBucket.grantWrite(pdfGenerateFunction);
+
+    // Python Lambda: Library Ingest
+    const libraryIngestFunction = new lambda.Function(this, 'LibraryIngestFunction', {
+      functionName: 'proposal-system-library-ingest',
+      runtime: lambda.Runtime.PYTHON_3_12,
+      architecture: lambda.Architecture.ARM_64,
+      handler: 'app.handler',
+      code: lambda.Code.fromAsset('../lambdas/library-ingest'),
+      memorySize: 512,
+      timeout: cdk.Duration.seconds(60),
+      vpc: props.vpc,
+      vpcSubnets: privateSubnets,
+      securityGroups: [props.lambdaSecurityGroup],
+      environment: {
+        LIBRARY_BUCKET: props.libraryBucket.bucketName,
+        API_BASE_URL: httpApi.apiEndpoint,
+      },
+    });
+
+    props.libraryBucket.grantWrite(libraryIngestFunction);
+    libraryIngestFunction.addToRolePolicy(new iam.PolicyStatement({
+      actions: ['bedrock:StartIngestionJob'],
+      resources: ['*'],
+    }));
+
+    // SQS Event Source for Python Lambdas
+    // All three consume from the same queue, routed by message attributes
+    // For now, use a single consumer that routes internally
+    // TODO: Phase 4 will refine this to use message filtering or separate queues per function
+    pdfExtractFunction.addEventSource(new lambdaEventSources.SqsEventSource(props.jobsQueue, {
+      batchSize: 1,
+      filters: [
+        lambda.FilterCriteria.filter({
+          body: { jobType: lambda.FilterRule.isEqual('pdf-extract') },
+        }),
+      ],
+    }));
+
+    pdfGenerateFunction.addEventSource(new lambdaEventSources.SqsEventSource(props.jobsQueue, {
+      batchSize: 1,
+      filters: [
+        lambda.FilterCriteria.filter({
+          body: { jobType: lambda.FilterRule.isEqual('pdf-generate') },
+        }),
+      ],
+    }));
+
+    libraryIngestFunction.addEventSource(new lambdaEventSources.SqsEventSource(props.jobsQueue, {
+      batchSize: 1,
+      filters: [
+        lambda.FilterCriteria.filter({
+          body: { jobType: lambda.FilterRule.isEqual('library-ingest') },
+        }),
+      ],
+    }));
+
+    // Outputs
+    new cdk.CfnOutput(this, 'ApiEndpoint', { value: httpApi.apiEndpoint });
+    new cdk.CfnOutput(this, 'ApiFunctionArn', { value: apiFunction.functionArn });
+  }
+}
diff --git a/infra/lib/foundation-stack.ts b/infra/lib/foundation-stack.ts
new file mode 100644
index 0000000..4040621
--- /dev/null
+++ b/infra/lib/foundation-stack.ts
@@ -0,0 +1,282 @@
+import * as cdk from 'aws-cdk-lib';
+import * as ec2 from 'aws-cdk-lib/aws-ec2';
+import * as rds from 'aws-cdk-lib/aws-rds';
+import * as s3 from 'aws-cdk-lib/aws-s3';
+import * as sqs from 'aws-cdk-lib/aws-sqs';
+import * as cognito from 'aws-cdk-lib/aws-cognito';
+import * as logs from 'aws-cdk-lib/aws-logs';
+import * as secretsmanager from 'aws-cdk-lib/aws-secretsmanager';
+import { Construct } from 'constructs';
+
+export class FoundationStack extends cdk.Stack {
+  public readonly vpc: ec2.IVpc;
+  public readonly lambdaSecurityGroup: ec2.ISecurityGroup;
+  public readonly dbSecret: secretsmanager.ISecret;
+  public readonly uploadsBucket: s3.IBucket;
+  public readonly generatedBucket: s3.IBucket;
+  public readonly libraryBucket: s3.IBucket;
+  public readonly jobsQueue: sqs.IQueue;
+  public readonly userPool: cognito.IUserPool;
+
+  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
+    super(scope, id, props);
+
+    // VPC: 2 AZs, public + private subnets, single NAT Gateway
+    this.vpc = new ec2.Vpc(this, 'Vpc', {
+      vpcName: 'proposal-system-vpc',
+      maxAzs: 2,
+      natGateways: 1,
+      subnetConfiguration: [
+        {
+          name: 'public',
+          subnetType: ec2.SubnetType.PUBLIC,
+          cidrMask: 24,
+        },
+        {
+          name: 'private',
+          subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS,
+          cidrMask: 24,
+        },
+      ],
+    });
+
+    // VPC Endpoints
+    this.vpc.addGatewayEndpoint('S3Endpoint', {
+      service: ec2.GatewayVpcEndpointAwsService.S3,
+    });
+
+    this.vpc.addInterfaceEndpoint('SecretsManagerEndpoint', {
+      service: ec2.InterfaceVpcEndpointAwsService.SECRETS_MANAGER,
+    });
+
+    // Security Groups
+    this.lambdaSecurityGroup = new ec2.SecurityGroup(this, 'LambdaSg', {
+      vpc: this.vpc,
+      securityGroupName: 'proposal-system-lambda-sg',
+      description: 'Security group for proposal system Lambda functions',
+      allowAllOutbound: true,
+    });
+
+    const rdsSg = new ec2.SecurityGroup(this, 'RdsSg', {
+      vpc: this.vpc,
+      securityGroupName: 'proposal-system-rds-sg',
+      description: 'Security group for proposal system RDS instance',
+      allowAllOutbound: false,
+    });
+
+    rdsSg.addIngressRule(
+      this.lambdaSecurityGroup,
+      ec2.Port.tcp(5432),
+      'Allow PostgreSQL from Lambda SG'
+    );
+
+    // RDS PostgreSQL 15
+    const dbInstance = new rds.DatabaseInstance(this, 'Database', {
+      instanceIdentifier: 'proposal-system-db',
+      engine: rds.DatabaseInstanceEngine.postgres({
+        version: rds.PostgresEngineVersion.VER_15,
+      }),
+      instanceType: ec2.InstanceType.of(
+        ec2.InstanceClass.T4G,
+        ec2.InstanceSize.SMALL
+      ),
+      vpc: this.vpc,
+      vpcSubnets: { subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS },
+      securityGroups: [rdsSg],
+      multiAz: false,
+      allocatedStorage: 20,
+      maxAllocatedStorage: 100,
+      storageEncrypted: true,
+      backupRetention: cdk.Duration.days(7),
+      deletionProtection: true,
+      removalPolicy: cdk.RemovalPolicy.RETAIN,
+      databaseName: 'proposals',
+      credentials: rds.Credentials.fromGeneratedSecret('proposalsadmin', {
+        secretName: 'proposal-system/db-credentials',
+      }),
+      publiclyAccessible: false,
+    });
+
+    this.dbSecret = dbInstance.secret!;
+
+    // S3 Buckets
+    this.uploadsBucket = new s3.Bucket(this, 'UploadsBucket', {
+      bucketName: `proposal-system-uploads-${this.account}`,
+      encryption: s3.BucketEncryption.S3_MANAGED,
+      versioned: true,
+      blockPublicAccess: s3.BlockPublicAccess.BLOCK_ALL,
+      lifecycleRules: [
+        {
+          transitions: [
+            {
+              storageClass: s3.StorageClass.INFREQUENT_ACCESS,
+              transitionAfter: cdk.Duration.days(90),
+            },
+          ],
+        },
+      ],
+      cors: [
+        {
+          allowedMethods: [s3.HttpMethods.PUT, s3.HttpMethods.POST],
+          allowedOrigins: ['*'],
+          allowedHeaders: ['*'],
+          maxAge: 3600,
+        },
+      ],
+      removalPolicy: cdk.RemovalPolicy.RETAIN,
+    });
+    cdk.Tags.of(this.uploadsBucket).add('Purpose', 'Vendor PDFs and dispatcher attachments');
+    cdk.Tags.of(this.uploadsBucket).add('ManagedBy', 'proposal-system');
+
+    this.generatedBucket = new s3.Bucket(this, 'GeneratedBucket', {
+      bucketName: `proposal-system-generated-${this.account}`,
+      encryption: s3.BucketEncryption.S3_MANAGED,
+      versioned: true,
+      blockPublicAccess: s3.BlockPublicAccess.BLOCK_ALL,
+      removalPolicy: cdk.RemovalPolicy.RETAIN,
+    });
+    cdk.Tags.of(this.generatedBucket).add('Purpose', 'Generated proposal PDFs');
+    cdk.Tags.of(this.generatedBucket).add('ManagedBy', 'proposal-system');
+
+    this.libraryBucket = new s3.Bucket(this, 'LibraryBucket', {
+      bucketName: `proposal-system-library-${this.account}`,
+      encryption: s3.BucketEncryption.S3_MANAGED,
+      versioned: true,
+      blockPublicAccess: s3.BlockPublicAccess.BLOCK_ALL,
+      removalPolicy: cdk.RemovalPolicy.RETAIN,
+    });
+    cdk.Tags.of(this.libraryBucket).add('Purpose', 'Historical proposal library for RAG');
+    cdk.Tags.of(this.libraryBucket).add('ManagedBy', 'proposal-system');
+
+    // SQS Queue + DLQ
+    const dlq = new sqs.Queue(this, 'JobsDlq', {
+      queueName: 'proposal-system-jobs-dlq',
+      retentionPeriod: cdk.Duration.days(14),
+    });
+
+    this.jobsQueue = new sqs.Queue(this, 'JobsQueue', {
+      queueName: 'proposal-system-jobs',
+      visibilityTimeout: cdk.Duration.seconds(180),
+      deadLetterQueue: {
+        queue: dlq,
+        maxReceiveCount: 3,
+      },
+    });
+
+    // Cognito User Pool
+    const userPool = new cognito.UserPool(this, 'UserPool', {
+      userPoolName: 'proposal-system-auth',
+      selfSignUpEnabled: false,
+      signInAliases: { email: true },
+      standardAttributes: {
+        email: { required: true, mutable: true },
+        fullname: { required: true, mutable: true },
+      },
+      passwordPolicy: {
+        minLength: 12,
+        requireUppercase: true,
+        requireLowercase: true,
+        requireDigits: true,
+        requireSymbols: false,
+      },
+      accountRecovery: cognito.AccountRecovery.EMAIL_ONLY,
+      removalPolicy: cdk.RemovalPolicy.RETAIN,
+    });
+
+    this.userPool = userPool;
+
+    // Cognito Groups
+    new cognito.CfnUserPoolGroup(this, 'DispatchersGroup', {
+      userPoolId: userPool.userPoolId,
+      groupName: 'dispatchers',
+      description: 'Dispatchers who submit proposal requests',
+    });
+
+    new cognito.CfnUserPoolGroup(this, 'AdminsGroup', {
+      userPoolId: userPool.userPoolId,
+      groupName: 'admins',
+      description: 'Admins who review and approve proposals',
+    });
+
+    new cognito.CfnUserPoolGroup(this, 'SysadminsGroup', {
+      userPoolId: userPool.userPoolId,
+      groupName: 'sysadmins',
+      description: 'System administrators',
+    });
+
+    // Cognito Domain
+    userPool.addDomain('CognitoDomain', {
+      cognitoDomain: { domainPrefix: 'proposal-system-seahaven' },
+    });
+
+    // Web App Client (PKCE)
+    userPool.addClient('WebClient', {
+      userPoolClientName: 'proposal-system-web',
+      generateSecret: false,
+      authFlows: {
+        userSrp: true,
+      },
+      oAuth: {
+        flows: { authorizationCodeGrant: true },
+        scopes: [
+          cognito.OAuthScope.OPENID,
+          cognito.OAuthScope.EMAIL,
+          cognito.OAuthScope.PROFILE,
+        ],
+        callbackUrls: [
+          'https://proposals.seahaven.com/callback',
+          'http://localhost:5173/callback',
+        ],
+        logoutUrls: [
+          'https://proposals.seahaven.com',
+          'http://localhost:5173',
+        ],
+      },
+    });
+
+    // Mobile App Client (PKCE)
+    userPool.addClient('MobileClient', {
+      userPoolClientName: 'proposal-system-mobile',
+      generateSecret: false,
+      authFlows: {
+        userSrp: true,
+      },
+      oAuth: {
+        flows: { authorizationCodeGrant: true },
+        scopes: [
+          cognito.OAuthScope.OPENID,
+          cognito.OAuthScope.EMAIL,
+          cognito.OAuthScope.PROFILE,
+        ],
+        callbackUrls: ['proposalsystem://callback'],
+        logoutUrls: ['proposalsystem://logout'],
+      },
+    });
+
+    // CloudWatch Log Groups
+    const logGroupNames = [
+      'proposal-system-api',
+      'proposal-system-pdf-extract',
+      'proposal-system-pdf-generate',
+      'proposal-system-library-ingest',
+    ];
+
+    for (const name of logGroupNames) {
+      new logs.LogGroup(this, `LogGroup-${name}`, {
+        logGroupName: `/aws/lambda/${name}`,
+        retention: logs.RetentionDays.TWO_MONTHS,
+        removalPolicy: cdk.RemovalPolicy.DESTROY,
+      });
+    }
+
+    // Outputs
+    new cdk.CfnOutput(this, 'VpcId', { value: this.vpc.vpcId });
+    new cdk.CfnOutput(this, 'UserPoolId', { value: userPool.userPoolId });
+    new cdk.CfnOutput(this, 'UserPoolArn', { value: userPool.userPoolArn });
+    new cdk.CfnOutput(this, 'UploadsBucketName', { value: this.uploadsBucket.bucketName });
+    new cdk.CfnOutput(this, 'GeneratedBucketName', { value: this.generatedBucket.bucketName });
+    new cdk.CfnOutput(this, 'LibraryBucketName', { value: this.libraryBucket.bucketName });
+    new cdk.CfnOutput(this, 'JobsQueueUrl', { value: this.jobsQueue.queueUrl });
+    new cdk.CfnOutput(this, 'DbSecretArn', { value: this.dbSecret.secretArn });
+  }
+}
diff --git a/infra/lib/frontend-stack.ts b/infra/lib/frontend-stack.ts
new file mode 100644
index 0000000..dd3a247
--- /dev/null
+++ b/infra/lib/frontend-stack.ts
@@ -0,0 +1,49 @@
+import * as cdk from 'aws-cdk-lib';
+import * as s3 from 'aws-cdk-lib/aws-s3';
+import * as cloudfront from 'aws-cdk-lib/aws-cloudfront';
+import * as cloudfrontOrigins from 'aws-cdk-lib/aws-cloudfront-origins';
+import { Construct } from 'constructs';
+
+export class FrontendStack extends cdk.Stack {
+  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
+    super(scope, id, props);
+
+    const siteBucket = new s3.Bucket(this, 'SiteBucket', {
+      bucketName: `proposal-system-web-${this.account}`,
+      encryption: s3.BucketEncryption.S3_MANAGED,
+      blockPublicAccess: s3.BlockPublicAccess.BLOCK_ALL,
+      removalPolicy: cdk.RemovalPolicy.DESTROY,
+      autoDeleteObjects: true,
+    });
+
+    const distribution = new cloudfront.Distribution(this, 'Distribution', {
+      comment: 'proposal-system-web',
+      defaultBehavior: {
+        origin: cloudfrontOrigins.S3BucketOrigin.withOriginAccessControl(siteBucket),
+        viewerProtocolPolicy: cloudfront.ViewerProtocolPolicy.REDIRECT_TO_HTTPS,
+        cachePolicy: cloudfront.CachePolicy.CACHING_OPTIMIZED,
+        responseHeadersPolicy: cloudfront.ResponseHeadersPolicy.SECURITY_HEADERS,
+      },
+      defaultRootObject: 'index.html',
+      errorResponses: [
+        {
+          httpStatus: 403,
+          responseHttpStatus: 200,
+          responsePagePath: '/index.html',
+          ttl: cdk.Duration.seconds(0),
+        },
+        {
+          httpStatus: 404,
+          responseHttpStatus: 200,
+          responsePagePath: '/index.html',
+          ttl: cdk.Duration.seconds(0),
+        },
+      ],
+      minimumProtocolVersion: cloudfront.SecurityPolicyProtocol.TLS_V1_2_2021,
+    });
+
+    new cdk.CfnOutput(this, 'DistributionId', { value: distribution.distributionId });
+    new cdk.CfnOutput(this, 'DistributionDomainName', { value: distribution.distributionDomainName });
+    new cdk.CfnOutput(this, 'SiteBucketName', { value: siteBucket.bucketName });
+  }
+}
diff --git a/infra/package-lock.json b/infra/package-lock.json
new file mode 100644
index 0000000..4b4ec1a
--- /dev/null
+++ b/infra/package-lock.json
@@ -0,0 +1,493 @@
+{
+  "name": "proposal-system-infra",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "proposal-system-infra",
+      "version": "1.0.0",
+      "dependencies": {
+        "aws-cdk-lib": "2.253.1",
+        "constructs": "^10.4.2"
+      },
+      "devDependencies": {
+        "@types/node": "^22.0.0",
+        "aws-cdk": "^2.1122.0",
+        "typescript": "~5.7.0"
+      }
+    },
+    "node_modules/@aws-cdk/asset-awscli-v1": {
+      "version": "2.2.273",
+      "resolved": "https://registry.npmjs.org/@aws-cdk/asset-awscli-v1/-/asset-awscli-v1-2.2.273.tgz",
+      "integrity": "sha512-X57HYUtHt9BQrlrzUNcMyRsDUCoakYNnY6qh5lNwRCHPtQoTfXmuISkfLk0AjLkcbS5lw1LLTQFiQhTDXfiTvg==",
+      "license": "Apache-2.0"
+    },
+    "node_modules/@aws-cdk/asset-node-proxy-agent-v6": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/@aws-cdk/asset-node-proxy-agent-v6/-/asset-node-proxy-agent-v6-2.1.2.tgz",
+      "integrity": "sha512-pDiuqH+qY3zM9lhhLjbKJ1tnKOHzQ2V4Wr/3qsxyKeKAkuPMI/BVGvZG1PbrikUw949cGVTfVEt4ETKKYnrj0Q==",
+      "license": "Apache-2.0"
+    },
+    "node_modules/@aws-cdk/cloud-assembly-schema": {
+      "version": "53.24.0",
+      "resolved": "https://registry.npmjs.org/@aws-cdk/cloud-assembly-schema/-/cloud-assembly-schema-53.24.0.tgz",
+      "integrity": "sha512-rCwsd0Y9z4CUmV5FhzjbO2MprXjKG0rxCACuLEY40lD+wInvgcHer0lSDo7Xq9Sxe/IoNe/Wxb2YP3GgxvT3GA==",
+      "bundleDependencies": [
+        "jsonschema",
+        "semver"
+      ],
+      "license": "Apache-2.0",
+      "dependencies": {
+        "jsonschema": "~1.4.1",
+        "semver": "^7.8.0"
+      },
+      "engines": {
+        "node": ">= 18.0.0"
+      }
+    },
+    "node_modules/@aws-cdk/cloud-assembly-schema/node_modules/jsonschema": {
+      "version": "1.4.1",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": "*"
+      }
+    },
+    "node_modules/@aws-cdk/cloud-assembly-schema/node_modules/semver": {
+      "version": "7.8.0",
+      "inBundle": true,
+      "license": "ISC",
+      "bin": {
+        "semver": "bin/semver.js"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
+    "node_modules/@types/node": {
+      "version": "22.19.19",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.19.19.tgz",
+      "integrity": "sha512-dyh/xO2Fh5bYrfWaaqGrRQQGkNdmYw6AmaAUvYeUMNTWQtvb796ikLdmTchRmOlOiIJ1TDXfWgVx1QkUlQ6Hew==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~6.21.0"
+      }
+    },
+    "node_modules/aws-cdk": {
+      "version": "2.1122.0",
+      "resolved": "https://registry.npmjs.org/aws-cdk/-/aws-cdk-2.1122.0.tgz",
+      "integrity": "sha512-AI2Ks9qioWLvBPD4IoEtTet3wUG/o/q6U3WR3VCQKH5sNYLLPALo8o9sermNpMnfd1OQkqhL20tp4cEyojrIZg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "cdk": "bin/cdk"
+      },
+      "engines": {
+        "node": ">= 18.0.0"
+      }
+    },
+    "node_modules/aws-cdk-lib": {
+      "version": "2.253.1",
+      "resolved": "https://registry.npmjs.org/aws-cdk-lib/-/aws-cdk-lib-2.253.1.tgz",
+      "integrity": "sha512-vy+hA15/ZfSQpivkNdlIn2ZDA2hesp3WJgmtIZJDFwu6xzwv7wH7glbAdu5xCHGcOjepOaTKZSvCPC6sN+0/Vw==",
+      "bundleDependencies": [
+        "@balena/dockerignore",
+        "@aws-cdk/cloud-assembly-api",
+        "case",
+        "fs-extra",
+        "ignore",
+        "jsonschema",
+        "minimatch",
+        "punycode",
+        "semver",
+        "table",
+        "yaml",
+        "mime-types"
+      ],
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@aws-cdk/asset-awscli-v1": "2.2.273",
+        "@aws-cdk/asset-node-proxy-agent-v6": "^2.1.1",
+        "@aws-cdk/cloud-assembly-api": "^2.2.2",
+        "@aws-cdk/cloud-assembly-schema": "^53.18.0",
+        "@balena/dockerignore": "^1.0.2",
+        "case": "1.6.3",
+        "fs-extra": "^11.3.3",
+        "ignore": "^5.3.2",
+        "jsonschema": "^1.5.0",
+        "mime-types": "^2.1.35",
+        "minimatch": "^10.2.3",
+        "punycode": "^2.3.1",
+        "semver": "^7.7.4",
+        "table": "^6.9.0",
+        "yaml": "1.10.3"
+      },
+      "engines": {
+        "node": ">= 20.0.0"
+      },
+      "peerDependencies": {
+        "constructs": "^10.5.0"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/@aws-cdk/cloud-assembly-api": {
+      "version": "2.2.2",
+      "bundleDependencies": [
+        "jsonschema",
+        "semver"
+      ],
+      "inBundle": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "jsonschema": "~1.4.1",
+        "semver": "^7.7.4"
+      },
+      "engines": {
+        "node": ">= 18.0.0"
+      },
+      "peerDependencies": {
+        "@aws-cdk/cloud-assembly-schema": ">=53.15.0"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/@balena/dockerignore": {
+      "version": "1.0.2",
+      "inBundle": true,
+      "license": "Apache-2.0"
+    },
+    "node_modules/aws-cdk-lib/node_modules/ajv": {
+      "version": "8.18.0",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "fast-deep-equal": "^3.1.3",
+        "fast-uri": "^3.0.1",
+        "json-schema-traverse": "^1.0.0",
+        "require-from-string": "^2.0.2"
+      },
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/epoberezkin"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/ansi-regex": {
+      "version": "5.0.1",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=8"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/ansi-styles": {
+      "version": "4.3.0",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "color-convert": "^2.0.1"
+      },
+      "engines": {
+        "node": ">=8"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/ansi-styles?sponsor=1"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/astral-regex": {
+      "version": "2.0.0",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=8"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/balanced-match": {
+      "version": "4.0.4",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": "18 || 20 || >=22"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/brace-expansion": {
+      "version": "5.0.5",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "balanced-match": "^4.0.2"
+      },
+      "engines": {
+        "node": "18 || 20 || >=22"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/case": {
+      "version": "1.6.3",
+      "inBundle": true,
+      "license": "(MIT OR GPL-3.0-or-later)",
+      "engines": {
+        "node": ">= 0.8.0"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/color-convert": {
+      "version": "2.0.1",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "color-name": "~1.1.4"
+      },
+      "engines": {
+        "node": ">=7.0.0"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/color-name": {
+      "version": "1.1.4",
+      "inBundle": true,
+      "license": "MIT"
+    },
+    "node_modules/aws-cdk-lib/node_modules/emoji-regex": {
+      "version": "8.0.0",
+      "inBundle": true,
+      "license": "MIT"
+    },
+    "node_modules/aws-cdk-lib/node_modules/fast-deep-equal": {
+      "version": "3.1.3",
+      "inBundle": true,
+      "license": "MIT"
+    },
+    "node_modules/aws-cdk-lib/node_modules/fast-uri": {
+      "version": "3.1.0",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/fastify"
+        },
+        {
+          "type": "opencollective",
+          "url": "https://opencollective.com/fastify"
+        }
+      ],
+      "inBundle": true,
+      "license": "BSD-3-Clause"
+    },
+    "node_modules/aws-cdk-lib/node_modules/fs-extra": {
+      "version": "11.3.3",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "graceful-fs": "^4.2.0",
+        "jsonfile": "^6.0.1",
+        "universalify": "^2.0.0"
+      },
+      "engines": {
+        "node": ">=14.14"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/graceful-fs": {
+      "version": "4.2.11",
+      "inBundle": true,
+      "license": "ISC"
+    },
+    "node_modules/aws-cdk-lib/node_modules/ignore": {
+      "version": "5.3.2",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">= 4"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/is-fullwidth-code-point": {
+      "version": "3.0.0",
+      "inBundle": true,
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+      "license": "MIT"
+    },
+    "node_modules/aws-cdk-lib/node_modules/jsonfile": {
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+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "universalify": "^2.0.0"
+      },
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+        "graceful-fs": "^4.1.6"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/jsonschema": {
+      "version": "1.5.0",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": "*"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/lodash.truncate": {
+      "version": "4.4.2",
+      "inBundle": true,
+      "license": "MIT"
+    },
+    "node_modules/aws-cdk-lib/node_modules/mime-db": {
+      "version": "1.52.0",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/mime-types": {
+      "version": "2.1.35",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "mime-db": "1.52.0"
+      },
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/minimatch": {
+      "version": "10.2.5",
+      "inBundle": true,
+      "license": "BlueOak-1.0.0",
+      "dependencies": {
+        "brace-expansion": "^5.0.5"
+      },
+      "engines": {
+        "node": "18 || 20 || >=22"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/isaacs"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/punycode": {
+      "version": "2.3.1",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=6"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/require-from-string": {
+      "version": "2.0.2",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/semver": {
+      "version": "7.7.4",
+      "inBundle": true,
+      "license": "ISC",
+      "bin": {
+        "semver": "bin/semver.js"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/slice-ansi": {
+      "version": "4.0.0",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "ansi-styles": "^4.0.0",
+        "astral-regex": "^2.0.0",
+        "is-fullwidth-code-point": "^3.0.0"
+      },
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/slice-ansi?sponsor=1"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/string-width": {
+      "version": "4.2.3",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "emoji-regex": "^8.0.0",
+        "is-fullwidth-code-point": "^3.0.0",
+        "strip-ansi": "^6.0.1"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/strip-ansi": {
+      "version": "6.0.1",
+      "inBundle": true,
+      "license": "MIT",
+      "dependencies": {
+        "ansi-regex": "^5.0.1"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/table": {
+      "version": "6.9.0",
+      "inBundle": true,
+      "license": "BSD-3-Clause",
+      "dependencies": {
+        "ajv": "^8.0.1",
+        "lodash.truncate": "^4.4.2",
+        "slice-ansi": "^4.0.0",
+        "string-width": "^4.2.3",
+        "strip-ansi": "^6.0.1"
+      },
+      "engines": {
+        "node": ">=10.0.0"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/universalify": {
+      "version": "2.0.1",
+      "inBundle": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">= 10.0.0"
+      }
+    },
+    "node_modules/aws-cdk-lib/node_modules/yaml": {
+      "version": "1.10.3",
+      "inBundle": true,
+      "license": "ISC",
+      "engines": {
+        "node": ">= 6"
+      }
+    },
+    "node_modules/constructs": {
+      "version": "10.6.0",
+      "resolved": "https://registry.npmjs.org/constructs/-/constructs-10.6.0.tgz",
+      "integrity": "sha512-TxHOnBO5zMo/G76ykzGF/wMpEHu257TbWiIxP9K0Yv/+t70UzgBQiTqjkAsWOPC6jW91DzJI0+ehQV6xDRNBuQ==",
+      "license": "Apache-2.0"
+    },
+    "node_modules/typescript": {
+      "version": "5.7.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.7.3.tgz",
+      "integrity": "sha512-84MVSjMEHP+FQRPy3pX9sTVV/INIex71s9TL2Gm5FG/WG1SqXeKyZ0k7/blY/4FdOzI12CBy1vGc4og/eus0fw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    },
+    "node_modules/undici-types": {
+      "version": "6.21.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.21.0.tgz",
+      "integrity": "sha512-iwDZqg0QAGrg9Rav5H4n0M64c3mkR59cJ6wQp+7C4nI0gsmExaedaYLNO44eT4AtBBwjbTiGPMlt2Md0T9H9JQ==",
+      "dev": true,
+      "license": "MIT"
+    }
+  }
+}
diff --git a/infra/package.json b/infra/package.json
new file mode 100644
index 0000000..b09d30a
--- /dev/null
+++ b/infra/package.json
@@ -0,0 +1,21 @@
+{
+  "name": "proposal-system-infra",
+  "version": "1.0.0",
+  "private": true,
+  "scripts": {
+    "build": "tsc",
+    "watch": "tsc -w",
+    "cdk": "cdk",
+    "synth": "cdk synth",
+    "deploy": "cdk deploy --all --require-approval never"
+  },
+  "dependencies": {
+    "aws-cdk-lib": "2.253.1",
+    "constructs": "^10.4.2"
+  },
+  "devDependencies": {
+    "@types/node": "^22.0.0",
+    "aws-cdk": "^2.1122.0",
+    "typescript": "~5.7.0"
+  }
+}
diff --git a/infra/tsconfig.json b/infra/tsconfig.json
new file mode 100644
index 0000000..bfe0f7d
--- /dev/null
+++ b/infra/tsconfig.json
@@ -0,0 +1,24 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "commonjs",
+    "lib": ["ES2022"],
+    "declaration": true,
+    "strict": true,
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "noImplicitThis": true,
+    "alwaysStrict": true,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": false,
+    "inlineSourceMap": true,
+    "inlineSources": true,
+    "experimentalDecorators": true,
+    "strictPropertyInitialization": false,
+    "outDir": "./dist",
+    "rootDir": "."
+  },
+  "exclude": ["node_modules", "cdk.out", "dist"]
+}
diff --git a/lambdas/library-ingest/app.py b/lambdas/library-ingest/app.py
new file mode 100644
index 0000000..6c4eaee
--- /dev/null
+++ b/lambdas/library-ingest/app.py
@@ -0,0 +1,14 @@
+"""Proposal System - Library Ingest Lambda.
+
+Processes approved proposals into the Bedrock Knowledge Base.
+Implementation in Phase 4.
+"""
+
+import json
+
+
+def handler(event, context):
+    for record in event.get("Records", []):
+        body = json.loads(record["body"])
+        print(f"Processing library-ingest job: {body}")
+    return {"statusCode": 200}
diff --git a/lambdas/library-ingest/requirements.txt b/lambdas/library-ingest/requirements.txt
new file mode 100644
index 0000000..97c4921
--- /dev/null
+++ b/lambdas/library-ingest/requirements.txt
@@ -0,0 +1 @@
+boto3>=1.35.0,<2.0
diff --git a/lambdas/pdf-extract/app.py b/lambdas/pdf-extract/app.py
new file mode 100644
index 0000000..42430aa
--- /dev/null
+++ b/lambdas/pdf-extract/app.py
@@ -0,0 +1,14 @@
+"""Proposal System - PDF Extract Lambda.
+
+Parses vendor proposal PDFs and extracts structured line item data.
+Implementation in Phase 4.
+"""
+
+import json
+
+
+def handler(event, context):
+    for record in event.get("Records", []):
+        body = json.loads(record["body"])
+        print(f"Processing pdf-extract job: {body}")
+    return {"statusCode": 200}
diff --git a/lambdas/pdf-extract/requirements.txt b/lambdas/pdf-extract/requirements.txt
new file mode 100644
index 0000000..1d64c16
--- /dev/null
+++ b/lambdas/pdf-extract/requirements.txt
@@ -0,0 +1,2 @@
+pdfplumber>=0.11.0,<1.0
+boto3>=1.35.0,<2.0
diff --git a/lambdas/pdf-generate/app.py b/lambdas/pdf-generate/app.py
new file mode 100644
index 0000000..b59ee6f
--- /dev/null
+++ b/lambdas/pdf-generate/app.py
@@ -0,0 +1,14 @@
+"""Proposal System - PDF Generate Lambda.
+
+Generates professional branded proposal PDFs from approved proposals.
+Implementation in Phase 5.
+"""
+
+import json
+
+
+def handler(event, context):
+    for record in event.get("Records", []):
+        body = json.loads(record["body"])
+        print(f"Processing pdf-generate job: {body}")
+    return {"statusCode": 200}
diff --git a/lambdas/pdf-generate/requirements.txt b/lambdas/pdf-generate/requirements.txt
new file mode 100644
index 0000000..64cd117
--- /dev/null
+++ b/lambdas/pdf-generate/requirements.txt
@@ -0,0 +1,2 @@
+reportlab>=4.2.0,<5.0
+boto3>=1.35.0,<2.0
diff --git a/mobile/package.json b/mobile/package.json
new file mode 100644
index 0000000..2ba72eb
--- /dev/null
+++ b/mobile/package.json
@@ -0,0 +1,17 @@
+{
+  "name": "proposal-system-mobile",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "start": "react-native start",
+    "ios": "react-native run-ios"
+  },
+  "dependencies": {
+    "react": "^19.0.0",
+    "react-native": "^0.76.0"
+  },
+  "devDependencies": {
+    "@types/react": "^19.0.0",
+    "typescript": "~5.7.0"
+  }
+}
diff --git a/shared/api-contracts/package.json b/shared/api-contracts/package.json
new file mode 100644
index 0000000..8d0bbef
--- /dev/null
+++ b/shared/api-contracts/package.json
@@ -0,0 +1,13 @@
+{
+  "name": "@proposal-system/api-contracts",
+  "version": "0.1.0",
+  "private": true,
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
+  "scripts": {
+    "typecheck": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "typescript": "~5.7.0"
+  }
+}
diff --git a/shared/api-contracts/src/index.ts b/shared/api-contracts/src/index.ts
new file mode 100644
index 0000000..8d8a600
--- /dev/null
+++ b/shared/api-contracts/src/index.ts
@@ -0,0 +1,61 @@
+export type ProposalStatus = 'Draft' | 'InReview' | 'Approved' | 'Sent' | 'Revised';
+export type ServiceCategory = 'HVAC' | 'Plumbing' | 'Electrical' | 'General' | 'Renovation';
+export type Priority = 'Standard' | 'Urgent' | 'Emergency';
+export type LineItemSource = 'AI' | 'Vendor' | 'Manual' | 'Historical';
+export type PricingMode = 'UnitPrice' | 'TotalPrice' | 'Both';
+export type UserRole = 'Dispatcher' | 'Admin' | 'SysAdmin';
+
+export interface Proposal {
+  id: string;
+  proposalNumber: string;
+  workOrderNumber: string;
+  customerName: string;
+  customerAddress: string;
+  scopeOfWork: string;
+  refinedScope: string | null;
+  serviceCategory: ServiceCategory;
+  priority: Priority;
+  status: ProposalStatus;
+  totalBidAmount: number;
+  vendorTotalCost: number | null;
+  notes: string;
+  submittedById: string;
+  submittedAt: string;
+  assignedAdminId: string | null;
+  approvedById: string | null;
+  approvedAt: string | null;
+  sentAt: string | null;
+  currentRevision: number;
+  parentProposalId: string | null;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface LineItem {
+  id: string;
+  proposalId: string;
+  description: string;
+  quantity: number;
+  unit: string;
+  unitPrice: number | null;
+  totalPrice: number;
+  pricingMode: PricingMode;
+  sortOrder: number;
+  source: LineItemSource;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface CreateProposalRequest {
+  workOrderNumber: string;
+  customerName: string;
+  customerAddress: string;
+  scopeOfWork: string;
+  serviceCategory: ServiceCategory;
+  priority: Priority;
+  notes?: string;
+}
+
+export interface UpdateLineItemsRequest {
+  lineItems: Omit<LineItem, 'id' | 'proposalId' | 'createdAt' | 'updatedAt'>[];
+}
diff --git a/shared/api-contracts/tsconfig.json b/shared/api-contracts/tsconfig.json
new file mode 100644
index 0000000..2c35d19
--- /dev/null
+++ b/shared/api-contracts/tsconfig.json
@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "declaration": true,
+    "outDir": "./dist",
+    "rootDir": "./src"
+  },
+  "include": ["src"]
+}
diff --git a/web/index.html b/web/index.html
new file mode 100644
index 0000000..7b7a1a9
--- /dev/null
+++ b/web/index.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Proposal System - Sea Haven Industries</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>
diff --git a/web/package.json b/web/package.json
new file mode 100644
index 0000000..b1d81a9
--- /dev/null
+++ b/web/package.json
@@ -0,0 +1,28 @@
+{
+  "name": "proposal-system-web",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc -b && vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "@emotion/react": "^11.14.0",
+    "@emotion/styled": "^11.14.0",
+    "@mui/material": "^7.0.0",
+    "@tanstack/react-query": "^5.60.0",
+    "axios": "^1.7.0",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
+    "react-router": "^7.0.0"
+  },
+  "devDependencies": {
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
+    "@vitejs/plugin-react": "^4.3.0",
+    "typescript": "~5.7.0",
+    "vite": "^6.0.0"
+  }
+}
diff --git a/web/src/main.tsx b/web/src/main.tsx
new file mode 100644
index 0000000..7c13e11
--- /dev/null
+++ b/web/src/main.tsx
@@ -0,0 +1,12 @@
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+
+function App() {
+  return <div>Proposal System</div>;
+}
+
+ReactDOM.createRoot(document.getElementById('root')!).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>
+);
diff --git a/web/tsconfig.json b/web/tsconfig.json
new file mode 100644
index 0000000..1bc6e12
--- /dev/null
+++ b/web/tsconfig.json
@@ -0,0 +1,21 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "useDefineForClassFields": true,
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "isolatedModules": true,
+    "moduleDetection": "force",
+    "noEmit": true,
+    "jsx": "react-jsx",
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedIndexedAccess": true
+  },
+  "include": ["src"]
+}
diff --git a/web/vite.config.ts b/web/vite.config.ts
new file mode 100644
index 0000000..5c59447
--- /dev/null
+++ b/web/vite.config.ts
@@ -0,0 +1,9 @@
+import { defineConfig } from 'vite';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig({
+  plugins: [react()],
+  server: {
+    port: 5173,
+  },
+});