feat: Woodpecker CI pipeline + project docs (P0-007, P0-008) (#69)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

CLAUDE.md

@@ -0,0 +1,45 @@
+# CLAUDE.md — Mosaic Stack
+
+## Project
+
+Self-hosted, multi-user AI agent platform. TypeScript monorepo.
+
+## Stack
+
+- **API**: NestJS + Fastify adapter (`apps/gateway`)
+- **Web**: Next.js 16 + React 19 (`apps/web`)
+- **ORM**: Drizzle ORM + PostgreSQL 17 + pgvector (`packages/db`)
+- **Auth**: BetterAuth (`packages/auth`)
+- **Agent**: Pi SDK (`packages/agent`, `packages/cli`)
+- **Queue**: Valkey 8 (`packages/queue`)
+- **Build**: pnpm workspaces + Turborepo
+- **CI**: Woodpecker CI
+- **Observability**: OpenTelemetry → Jaeger
+
+## Commands
+
+```bash
+pnpm typecheck        # TypeScript check (all packages)
+pnpm lint             # ESLint (all packages)
+pnpm format:check     # Prettier check
+pnpm test             # Vitest (all packages)
+pnpm build            # Build all packages
+
+# Database
+pnpm --filter @mosaic/db db:push      # Push schema to PG (dev)
+pnpm --filter @mosaic/db db:generate  # Generate migrations
+pnpm --filter @mosaic/db db:migrate   # Run migrations
+
+# Dev
+docker compose up -d                  # Start PG, Valkey, OTEL, Jaeger
+pnpm --filter @mosaic/gateway exec tsx src/main.ts  # Start gateway
+```
+
+## Conventions
+
+- ESM everywhere (`"type": "module"`, `.js` extensions in imports)
+- NodeNext module resolution
+- Explicit `@Inject()` decorators in NestJS (tsx/esbuild doesn't support emitDecoratorMetadata)
+- DTOs in `*.dto.ts` files at module boundaries
+- OTEL tracing imported before NestJS bootstrap (`import './tracing.js'`)
+- All three gates must pass before push: typecheck, lint, format:check