feat: add env setup wizard, fix docker-compose env passthrough and email from field

- Add interactive setup wizard (scripts/setup-env.js) with SQLite/PostgreSQL
  choice, AI provider config, email, MCP, admin account creation, and
  auto-switch of Prisma schema provider
- Fix docker-compose.yml: remove duplicate environment entries that overrode
  env_file values with empty strings (broke AI providers in Docker). Now only
  DATABASE_URL, NODE_ENV, NEXT_TELEMETRY_DISABLED remain in environment:
- Fix revalidateTag('system-config', '/settings') crash: Next.js 16 interprets
  the second arg as a cacheLife profile, not a path. Caused 500 on all admin
  settings saves
- Fix Resend "from" field: was building noreply@localhost which Resend rejects.
  Now uses SMTP_FROM from config, with localhost-aware fallback
- Add debug logging for auto-labeling background task
- Default DATABASE_URL changed from user:password to memento:memento

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

memento-note/.env.example

@@ -6,7 +6,7 @@
 # -----------------------------------------------------------------------------
 # Core (required)
 # -----------------------------------------------------------------------------
-DATABASE_URL="postgresql://user:password@localhost:5432/memento"
+DATABASE_URL="postgresql://memento:memento@localhost:5432/memento"
 NEXTAUTH_SECRET="generate-with-openssl-rand-base64-32"
 NEXTAUTH_URL="http://localhost:3000"