- Fix monthly_reset_at crash when billing anchor day exceeds next month's length
- Add environment_tags sanitization (max 20 tags, 100 chars each) to prevent prompt injection
- Add @limiter.limit("10/minute") rate limiting to all AI endpoints
- Use getTreeNavigatePath() routing helper instead of hardcoded paths
- Extract shared CreateFlowDropdown component from QuickStartPage and TreeLibraryPage
- Clear useCachedQuota on logout to prevent stale data across user sessions
- Add useRef guard to scaffold useEffect to prevent potential double-fire
- Use node.id as React key instead of array index in BranchDetailView
- Remove redundant dead logic in ai_tree_validator
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Implements the complete AI flow builder feature using a guided 4-stage
wizard (Foundation → Scaffold → Branch Detail → Review & Assemble).
AI assists at bounded points using Claude Haiku for cost-efficient
structured JSON generation (~$0.01-0.03/flow).
Backend: new models (ai_conversations, ai_usage), Alembic migration,
quota enforcement with billing anchor, Anthropic API integration with
prompt caching, tree validation, conversation CRUD with 24h TTL,
APScheduler cleanup job, 5 API endpoints, Pydantic schemas.
Frontend: TypeScript types, API client, Zustand store for wizard state,
7 components (modal, step indicator, foundation form, branch selector,
branch detail view, tree preview, quota display), MyTreesPage integration
with "Build with AI" button (hidden when AI not configured).
Tests: 14 validator unit tests + 11 endpoint integration tests with
mocked Anthropic (zero real API spend). All 25 tests passing.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
