feat(14-02): update Dockerfile for PostgreSQL (remove native build deps)

- Remove apt-get install of python3/make/g++ (no longer needed without better-sqlite3)
- Change COPY drizzle to COPY drizzle-pg for PostgreSQL migrations
- Remove mkdir -p data (no SQLite data directory needed)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -1,6 +1,5 @@
 FROM oven/bun:1 AS deps
 WORKDIR /app
-RUN apt-get update && apt-get install -y python3 make g++ && rm -rf /var/lib/apt/lists/*
 COPY package.json bun.lock ./
 RUN bun install --frozen-lockfile
 
@@ -17,9 +16,9 @@ COPY src/server ./src/server
 COPY src/db ./src/db
 COPY src/shared ./src/shared
 COPY drizzle.config.ts package.json ./
-COPY drizzle ./drizzle
+COPY drizzle-pg ./drizzle-pg
 COPY entrypoint.sh ./
-RUN chmod +x entrypoint.sh && mkdir -p data uploads
+RUN chmod +x entrypoint.sh && mkdir -p uploads
 EXPOSE 3000
 HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
   CMD bun -e "fetch('http://localhost:3000/api/health').then(r=>r.ok?process.exit(0):process.exit(1)).catch(()=>process.exit(1))"