feat(docker): add all-in-one multi-arch Dockerfile and Gitea deploy config

- Dockerfile.all-in-one: self-contained multi-stage build (frontend, Rust
  native cross-compile with Debian cross-GCC, server bundle, prod deps,
  runtime) for linux/amd64 + linux/arm64
- Fix aws-lc-sys asm build on arm64: use gcc-aarch64-linux-gnu instead of
  napi-rs cross-toolchain (bundled GCC 4.8.5 lacks __ARM_ARCH)
- Reduce memory via CARGO_PROFILE_RELEASE_LTO=thin + codegen-units=8
- Runtime mirrors upstream layout incl. schema.prisma/migrations so the
  selfhost predeploy job works; installs openssl + libjemalloc2
- scripts/deploy-gitea.sh + .gitea-deploy: build/push to Gitea registry
- .dockerignore: exclude dist/node_modules/tsbuildinfo from context

.dockerignore

@@ -11,6 +11,9 @@
 /.yarn/unplugged
 /.yarn/install-state.gz
 /.pnp.*
+**/dist
+**/node_modules
+**/*.tsbuildinfo
 
 # Test artifacts
 /test-results