feat(security): credentialed exec + HTTP RBAC + API key cache (#197)

- Secure CLI credential injection via AES-256-GCM encrypted env vars
- API key management with fine-grained RBAC scopes
- resolveAuth/requireAuth middleware across all 25+ HTTP handlers
- In-memory API key cache with TTL, negative caching, pubsub invalidation
- Sandbox-first execution (fails if unavailable, no silent fallback)
- Credential scrubbing, constant-time token comparison, Admin-only CLI creds
- SQL migration 000020: secure_cli_binaries + api_keys tables
- 14 unit tests for cache and RBAC with race detector

Closes #197

.github/workflows/claude-code-review.yml

@@ -35,7 +35,7 @@ jobs:
         id: claude-review
         uses: anthropics/claude-code-action@v1
         with:
-          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
           plugin_marketplaces: 'https://github.com/anthropics/claude-code.git'
           plugins: 'code-review@claude-code-plugins'
           prompt: '/code-review:code-review ${{ github.repository }}/pull/${{ github.event.pull_request.number }}'

.github/workflows/claude.yml

@@ -34,7 +34,7 @@ jobs:
         id: claude
         uses: anthropics/claude-code-action@v1
         with:
-          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
 
           # This is an optional setting that allows Claude to read CI results on PRs
           additional_permissions: |