fix(infra): scope Bedrock model ARN, AOSS permissions, require deploy approval (INF-M1, M2, M9)

INF-M1: Replace wildcard anthropic.claude-* foundation-model ARN with the
specific cross-region inference profile ARN and its backing foundation model.
Both suggestions and pdf-extract Lambdas use us.anthropic.claude-sonnet-4-5-20250929-v1:0.

INF-M2: Replace aoss:* data access policy permissions with scoped actions.
KB role gets DescribeCollectionItems/CreateCollectionItems/UpdateCollectionItems
on collection and DescribeIndex/ReadDocument/WriteDocument on indexes.
Index creator gets CreateIndex/DescribeIndex/WriteDocument plus collection describe/create.

INF-M9: Change --require-approval never to --require-approval broadening in
infra/package.json deploy script so IAM/security changes require manual
confirmation during local development.

AUDIT-REPORT.md

@@ -3,7 +3,7 @@
 **Date:** 2026-05-27
 **Auditor:** Claude Code (6 parallel specialist agents)
 **Scope:** Full monorepo — API, Web, Mobile, Lambdas, Infrastructure/CI/CD, QA/Testing
-**Remediation Status:** Phase 1-5 complete (2026-05-27). All Critical and High findings fixed. 17 Medium findings fixed. CI pipeline runs all 108 tests. Test infrastructure bootstrapped.
+**Remediation Status:** Phase 1-6 complete (2026-05-27). All Critical and High findings fixed. 20 Medium findings fixed. CI pipeline runs all 108 tests. Test infrastructure bootstrapped.
 
 ---
 
@@ -178,12 +178,13 @@ All items below have been remediated:
 
 | ID | Finding | Status |
 |----|---------|--------|
-| INF-M1-M2 | Bedrock wildcard model ARN, AOSS `aoss:*` permissions | |
+| INF-M1 | Bedrock wildcard model ARN | **FIXED** — scoped to specific inference profile + foundation model ARN |
+| INF-M2 | AOSS `aoss:*` data access permissions | **FIXED** — scoped to specific actions per principal (KB role vs index creator) |
 | INF-M3-M4 | No Cognito advanced security, Google OAuth not in CDK | |
 | INF-M5 | No S3 enforceSSL | **FIXED** — `enforceSSL: true` on all 4 buckets |
 | INF-M6-M7 | No custom domain on CF, no WAF | |
 | INF-M8 | Workflows pinned to @main | **FIXED** — SHA-pinned across all 3 workflow files |
-| INF-M9 | `--require-approval never` locally | |
+| INF-M9 | `--require-approval never` locally | **FIXED** — changed to `--require-approval broadening` |
 
 ---
 
@@ -269,10 +270,15 @@ Validators tested (36 tests). Lambda handlers tested (19 pytest tests for pdf-ge
 48. ~~INF-M5~~ — DONE (enforceSSL on all 4 S3 buckets)
 49. ~~INF-M8~~ — DONE (SHA-pinned workflow refs in all 3 workflow files)
 
-### Phase 6 — Remaining (not yet started)
+### Phase 6 — Infrastructure Medium Fixes (INF-M1, M2, M9)
+50. ~~INF-M1~~ — DONE (Bedrock IAM scoped to specific inference profile ARN)
+51. ~~INF-M2~~ — DONE (AOSS data access policy scoped per principal)
+52. ~~INF-M9~~ — DONE (`--require-approval broadening` in deploy script)
+
+### Phase 7 — Remaining (not yet started)
 - WEB-H1: Token refresh mechanism (requires backend refresh token flow)
 - Mobile High findings (MOB-H1 through H4): separate release cycle
-- Remaining Medium findings: API-M1/M2/M5/M7/M9/M10/M12/M13, WEB-M1/M3/M4/M8/M9/M11/M12, LAM-M2-M4/M6-M7/M9-M14, INF-M1-M4/M6-M7/M9
+- Remaining Medium findings: API-M1/M2/M5/M7/M9/M10/M12/M13, WEB-M1/M3/M4/M8/M9/M11/M12, LAM-M2-M4/M6-M7/M9-M14, INF-M3-M4/M6-M7
 - QA-C6: Mobile test coverage
 
 ---

infra/lib/compute-stack.ts

@@ -132,16 +132,61 @@ export class ComputeStack extends cdk.Stack {
       resources: [ossCollection.attrArn],
     }));
 
+    // Fix: INF-M2 — scope AOSS data access policy permissions (was aoss:* on both
+    // collection and index). KB role needs read/write for embeddings. Index creator
+    // needs create/describe for bootstrapping the vector index.
     const ossDataAccessPolicy = new opensearchserverless.CfnAccessPolicy(this, 'OssDataAccessPolicy', {
       name: 'proposal-system-kb-access',
       type: 'data',
-      policy: JSON.stringify([{
-        Rules: [
-          { ResourceType: 'collection', Resource: ['collection/proposal-system-kb'], Permission: ['aoss:*'] },
-          { ResourceType: 'index', Resource: ['index/proposal-system-kb/*'], Permission: ['aoss:*'] },
-        ],
-        Principal: [kbRole.roleArn, indexCreatorFn.role!.roleArn],
-      }]),
+      policy: JSON.stringify([
+        {
+          Description: 'Bedrock KB role — read/write documents and describe collection',
+          Rules: [
+            {
+              ResourceType: 'collection',
+              Resource: ['collection/proposal-system-kb'],
+              Permission: [
+                'aoss:DescribeCollectionItems',
+                'aoss:CreateCollectionItems',
+                'aoss:UpdateCollectionItems',
+              ],
+            },
+            {
+              ResourceType: 'index',
+              Resource: ['index/proposal-system-kb/*'],
+              Permission: [
+                'aoss:DescribeIndex',
+                'aoss:ReadDocument',
+                'aoss:WriteDocument',
+              ],
+            },
+          ],
+          Principal: [kbRole.roleArn],
+        },
+        {
+          Description: 'Index creator Lambda — create and describe index during bootstrap',
+          Rules: [
+            {
+              ResourceType: 'collection',
+              Resource: ['collection/proposal-system-kb'],
+              Permission: [
+                'aoss:DescribeCollectionItems',
+                'aoss:CreateCollectionItems',
+              ],
+            },
+            {
+              ResourceType: 'index',
+              Resource: ['index/proposal-system-kb/*'],
+              Permission: [
+                'aoss:CreateIndex',
+                'aoss:DescribeIndex',
+                'aoss:WriteDocument',
+              ],
+            },
+          ],
+          Principal: [indexCreatorFn.role!.roleArn],
+        },
+      ]),
     });
     ossDataAccessPolicy.addDependency(ossCollection);
 
@@ -354,9 +399,14 @@ export class ComputeStack extends cdk.Stack {
     internalApiKeySecret.grantRead(suggestionsFunction);
     // Fix: LAM-C1/INF-H1 — grant Function URL invoke permission for IAM auth
     apiFunctionUrl.grantInvokeUrl(suggestionsFunction);
+    // Fix: INF-M1 — scope Bedrock model ARN to the specific inference profile used
+    // (was wildcard anthropic.claude-*). Lambda MODEL_ID is a cross-region inference profile.
     suggestionsFunction.addToRolePolicy(new iam.PolicyStatement({
       actions: ['bedrock:InvokeModel'],
-      resources: [`arn:aws:bedrock:us-east-1::foundation-model/anthropic.claude-*`],
+      resources: [
+        `arn:aws:bedrock:us-east-1:${this.account}:inference-profile/us.anthropic.claude-sonnet-4-5-20250929-v1:0`,
+        `arn:aws:bedrock:us-east-1::foundation-model/anthropic.claude-sonnet-4-5-20250929-v1:0`,
+      ],
     }));
     suggestionsFunction.addToRolePolicy(new iam.PolicyStatement({
       actions: ['bedrock:Retrieve'],
@@ -388,9 +438,13 @@ export class ComputeStack extends cdk.Stack {
     // Fix: LAM-C1/INF-H1 — grant Function URL invoke permission for IAM auth
     apiFunctionUrl.grantInvokeUrl(pdfExtractFunction);
     props.uploadsBucket.grantRead(pdfExtractFunction);
+    // Fix: INF-M1 — scope Bedrock model ARN to the specific inference profile used
     pdfExtractFunction.addToRolePolicy(new iam.PolicyStatement({
       actions: ['bedrock:InvokeModel'],
-      resources: [`arn:aws:bedrock:us-east-1::foundation-model/anthropic.claude-*`],
+      resources: [
+        `arn:aws:bedrock:us-east-1:${this.account}:inference-profile/us.anthropic.claude-sonnet-4-5-20250929-v1:0`,
+        `arn:aws:bedrock:us-east-1::foundation-model/anthropic.claude-sonnet-4-5-20250929-v1:0`,
+      ],
     }));
 
     // Python Lambda: PDF Generate

infra/package.json

@@ -7,7 +7,7 @@
     "watch": "tsc -w",
     "cdk": "cdk",
     "synth": "cdk synth",
-    "deploy": "cdk deploy --all --require-approval never"
+    "deploy": "cdk deploy --all --require-approval broadening"
   },
   "dependencies": {
     "aws-cdk-lib": "2.257.0",