feat: add CI/CD pipeline, production Dockerfile, and deployment architecture

- Add production Dockerfile with bun build --compile, multi-stage Alpine build
- Add .dockerignore
- Swap bcrypt -> bcryptjs (pure JS, no native addons)
- Add programmatic migrations on startup via drizzle migrator
- Add /v1/version endpoint with APP_VERSION baked in at build time
- Add .gitea/workflows/ci.yml (lint + test with postgres/valkey services)
- Add .gitea/workflows/build.yml (version bump, build, push to registry)
- Update CLAUDE.md and docs/architecture.md to remove multi-tenancy
- Add docs/deployment.md covering DOKS + ArgoCD architecture

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/backend/src/routes/v1/auth.ts

@@ -1,6 +1,6 @@
 import type { FastifyPluginAsync } from 'fastify'
 import { eq } from 'drizzle-orm'
-import bcrypt from 'bcrypt'
+import bcrypt from 'bcryptjs'
 import { RegisterSchema, LoginSchema } from '@lunarfront/shared/schemas'
 import { users } from '../../db/schema/users.js'