INFRA-59: add org issue templates (bug, feature, infra-change) + config

Adds .github/ISSUE_TEMPLATE/ with bug_report.md, feature_request.md,
infra-change.md (change-control: impact, rollback plan, affected stacks),
and config.yml disabling blank issues + routing ops to INFRA Jira.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,27 @@
+---
+name: Bug report
+about: Report a defect in a Sea Haven service
+title: "[Bug] "
+labels: [bug, needs-triage]
+assignees: amoussa1229
+---
+
+## What's wrong
+<!-- Clear description of the bug. -->
+
+## Expected behavior
+<!-- What should happen instead. -->
+
+## Steps to reproduce
+1.
+2.
+3.
+
+## Environment / blast radius
+- Repo / service:
+- CFN stack affected:
+- Lambda(s) affected:
+- Region: us-east-1 (account 328440206208)
+
+## Logs / evidence
+<!-- CloudWatch log group + timestamp, request IDs, screenshots. -->

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Internal IT support
+    url: https://seahaven.atlassian.net/jira/software/projects/INFRA
+    about: For operational issues, file an INFRA Jira ticket instead.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,21 @@
+---
+name: Feature request
+about: Propose new functionality for a Sea Haven service
+title: "[Feature] "
+labels: [enhancement, needs-triage]
+assignees: amoussa1229
+---
+
+## Problem / motivation
+<!-- What operational pain or gap does this address? -->
+
+## Proposed solution
+<!-- What you want to build. -->
+
+## AWS / integration impact
+- New or changed AWS resources (Lambda, DynamoDB, S3, API Gateway):
+- Slack app(s) involved:
+- Confluence Architecture Map update needed: yes / no
+
+## Alternatives considered
+<!-- Other approaches and why they were rejected. -->

.github/ISSUE_TEMPLATE/infra-change.md

@@ -0,0 +1,26 @@
+---
+name: Infrastructure change
+about: Track a change to AWS infrastructure or integrations (change control)
+title: "[Infra] "
+labels: [infra, needs-triage]
+assignees: amoussa1229
+---
+
+## Change summary
+<!-- What is changing and why. -->
+
+## Impact assessment
+- **CFN stack affected:**
+- **Lambda(s) affected (handler signature change? Y/N):**
+- **DynamoDB table(s) affected (PITR verified? Y/N):**
+- **S3 bucket(s) / SES rules affected:**
+- **Slack app affected:**
+- **IAM role / policy changes (requires cross-review? Y/N):**
+
+## Rollback plan
+<!-- Exact steps to revert: prior stack version, DeletionPolicy considerations, data restore. -->
+
+## Documentation
+- [ ] Confluence Architecture Map (id 1540098) update queued
+- [ ] README updated in same PR
+- [ ] Project memory entry queued