v1.0.0 — Hexagonal architecture rewrite

Restructure the monolithic 252-line main.rs into a 10-crate workspace
with clean hexagonal architecture, swappable adapters, and a production-
ready deployment pipeline.

Backend architecture:
- domain: Canvas, Color/Position/PixelUpdate value objects, port traits
  (CanvasStore, CanvasPersistence, EventBroadcaster), BroadcastEvent
- application: use cases (place_pixel, get_state, save/restore snapshot,
  connect/disconnect), AppState with Arc snapshot cache
- config: AppConfig structs + ConfigSource trait
- api-types: shared DTOs, event name constants
- adapters: config-env, canvas-file, http-axum (rust-embed), socketio,
  websocket — all behind port traits, swappable via feature flags
- server: composition root with graceful shutdown (SIGTERM/SIGINT)

Frontend:
- Transport abstraction: Socket.IO and native WebSocket via VITE_TRANSPORT
- Canvas zoom/pan with mouse wheel, pinch-to-zoom, and +/- buttons
- ImageData rendering (~50x faster than fillRect loop)
- Touch support, responsive CSS scaling, mobile-friendly layout
- OG/Twitter Card meta tags for rich link previews

Production:
- Docker: musl static build on scratch — 2.73MB image
- CI workflows for Gitea and GitHub Actions (fmt, clippy, test, Docker push)
- deploy.sh for private registry
- 39 unit tests across domain and application
- Zero unwraps, zero unsafe, graceful error handling with tracing
- Periodic canvas snapshots with rotation, restored on startup
- All config via environment variables with typed defaults

Cargo.toml

@@ -1,22 +1,60 @@
-[package]
-name = "painter"
-version = "0.1.0"
-edition = "2021"
+[workspace]
+members = [
+    "crates/config",
+    "crates/domain",
+    "crates/application",
+    "crates/api-types",
+    "crates/adapters/canvas-file",
+    "crates/adapters/config-env",
+    "crates/adapters/http-axum",
+    "crates/adapters/socketio",
+    "crates/adapters/websocket",
+    "crates/server",
+]
+default-members = [
+    "crates/config",
+    "crates/domain",
+    "crates/application",
+    "crates/api-types",
+    "crates/adapters/canvas-file",
+    "crates/adapters/config-env",
+    "crates/adapters/http-axum",
+    "crates/server",
+]
+resolver = "2"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[workspace.package]
+version = "1.0.0"
+edition = "2024"
 
-[dependencies]
-axum = "0.7.5"
-bincode = "1.3.3"
-bytes = "1.6.0"
-chrono = "0.4.38"
+[workspace.dependencies]
+config = { path = "crates/config" }
+domain = { path = "crates/domain" }
+application = { path = "crates/application" }
+api-types = { path = "crates/api-types" }
+canvas-file = { path = "crates/adapters/canvas-file" }
+config-env = { path = "crates/adapters/config-env" }
+http-axum = { path = "crates/adapters/http-axum" }
+socketio = { path = "crates/adapters/socketio" }
+websocket = { path = "crates/adapters/websocket" }
+futures = "0.3"
+
+axum = "0.8.9"
 dotenv = "0.15.0"
-memory-stats = "1.1.0"
-serde = { version = "1.0.201", features = ["derive"] }
-serde_json = "1.0.117"
-socketioxide = "0.13.1"
-tokio = { version = "1.37.0", features = ["full"] }
-tower-http = { version = "0.5.2", features = ["cors", "fs"] }
-tower_governor = "0.4.2"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+socketioxide = "0.18.6"
+thiserror = "2"
+tokio = { version = "1.37", features = ["full"] }
+rust-embed = { version = "8", features = ["interpolate-folder-path", "mime-guess"] }
+tower-http = { version = "0.7.0", features = ["cors"] }
+tower_governor = "0.8.0"
 tracing = "0.1.40"
 tracing-subscriber = "0.3.18"
+
+[profile.release]
+lto = true
+opt-level = "z"
+codegen-units = 1
+panic = "abort"
+strip = true