chore(01-01): scaffold monorepo, Docker Compose stack, and Vitest harness

- pnpm workspace with apps/api (Hono/Drizzle) and apps/pwa (Vite/React 19)
- Pinned versions per RESEARCH: hono@4.12.23, drizzle-orm@0.45.2, mysql2@3.22.4, tsdav@2.2.2, ical.js@2.2.1, zod@^3.25.0, node-cron@^4.2.1
- docker-compose.yml with mariadb:11 healthcheck, api depends_on service_healthy, redis stub
- docker-compose.dev.yml overrides for local dev (bind mounts, exposed ports)
- .env.example lists all env vars (DB_*, OIDC_*, APP_PASSWORD_ENCRYPTION_KEY)
- .gitignore excludes .env (never commit secrets)
- apps/api/vitest.config.ts with environment: node
- Wave 0 test stubs: health, auth/user, broker/crypto, broker/sync, broker/poller

docker-compose.dev.yml

@@ -0,0 +1,18 @@
+# Local dev overrides — use with: docker compose -f docker-compose.yml -f docker-compose.dev.yml up
+services:
+  api:
+    build:
+      context: ./apps/api
+      target: dev
+    volumes:
+      - ./apps/api/src:/app/src
+    environment:
+      NODE_ENV: development
+
+  mariadb:
+    ports:
+      - "3306:3306"
+
+  redis:
+    ports:
+      - "6379:6379"