Local useState resets to 0 every time phase transitions from 'generating'
back to 'detailing', causing the view to snap back to branch 1.
Move viewingIndex to store's currentBranchIndex (already existed) and
advance it in generateBranchDetail after success. Component reads from
store so remounts no longer lose position.
Co-Authored-By: Claude Sonnet 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>
