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>

CLAUDE.md

@@ -24,8 +24,7 @@
 ## Database
 - Dev: `lunarfront` on localhost:5432
 - Test: `lunarfront_test` on localhost:5432
-- Multi-tenant: `company_id` (uuid FK) on all domain tables for tenant isolation
-- `location_id` (uuid FK) on tables that need per-location scoping (inventory, transactions, drawer)
+- Each deployed instance has its own isolated database — no multi-tenancy, no `company_id`
 - Migrations via Drizzle Kit (`bunx drizzle-kit generate`, `bunx drizzle-kit migrate`)
 
 ## Key Entity Names