Initial project setup for PhaseFlow

Set up Next.js 16 project with TypeScript for a training decision app
that integrates menstrual cycle phases with Garmin biometrics for
Hashimoto's thyroiditis management.

Stack: Next.js 16, React 19, Tailwind/shadcn, PocketBase, Drizzle,
Zod, Resend, Vitest, Biome, Lefthook, Nix dev environment.

Includes:
- 7 page routes (dashboard, login, settings, calendar, history, plan)
- 12 API endpoints (garmin, user, cycle, calendar, overrides, cron)
- Core lib utilities (decision engine, cycle phases, nutrition, ICS)
- Type definitions and component scaffolding
- Python script for Garmin token bootstrapping
- Initial unit tests for cycle utilities

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lefthook.yml

@@ -0,0 +1,9 @@
+# ABOUTME: Pre-commit hooks configuration for code quality enforcement.
+# ABOUTME: Runs biome linting and vitest tests before allowing commits.
+pre-commit:
+  parallel: true
+  commands:
+    lint:
+      run: pnpm biome check --staged --no-errors-on-unmatched
+    test:
+      run: pnpm test:run