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>

.gitea/workflows/ci.yml

@@ -0,0 +1,61 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    container:
+      image: registry.lunarfront.tech/ryan/ci-runner:latest
+      credentials:
+        username: ryan
+        password: ${{ secrets.REGISTRY_TOKEN }}
+
+    services:
+      postgres:
+        image: postgres:16
+        env:
+          POSTGRES_USER: lunarfront
+          POSTGRES_PASSWORD: lunarfront
+          POSTGRES_DB: lunarfront_test
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 5s
+          --health-timeout 3s
+          --health-retries 5
+
+      valkey:
+        image: valkey/valkey:8
+        options: >-
+          --health-cmd "valkey-cli ping"
+          --health-interval 5s
+          --health-timeout 3s
+          --health-retries 5
+
+    env:
+      DATABASE_URL: postgresql://lunarfront:lunarfront@postgres:5432/lunarfront_test
+      REDIS_URL: redis://valkey:6379
+      JWT_SECRET: ci-secret
+      NODE_ENV: test
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: bun install --frozen-lockfile
+
+      - name: Lint
+        run: bun run lint
+
+      - name: Run migrations
+        working-directory: packages/backend
+        run: bunx drizzle-kit migrate
+
+      - name: Test
+        run: bun run test