feat: migrate from PocketBase to PostgreSQL with Drizzle ORM

- Add @project-e/db package with Drizzle schema and migrations
- Replace PocketBase client with PostgreSQL-based database client
- Migrate auth from custom to NextAuth.js
- Add Docker Compose with PostgreSQL container
- Update worker to use new database client
- Remove PocketBase-specific files and migrations
- Add drizzle config and initial migration

drizzle.config.ts

@@ -0,0 +1,10 @@
+import { defineConfig } from 'drizzle-kit';
+
+export default defineConfig({
+  dialect: 'postgresql',
+  schema: './packages/db/src/schema.ts',
+  out: './drizzle',
+  dbCredentials: {
+    url: process.env.DATABASE_URL || 'postgresql://project_e:project_e@localhost:5432/project_e',
+  },
+});