Add convenience Makefile for building frontend and backend

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XFUNZwCvz3kcod3352ZR2o

Makefile

@@ -0,0 +1,42 @@
+.PHONY: all build build-fe build-be test test-fe test-be lint lint-fe lint-be run dev clean
+
+all: build
+
+# Build the webapp first so `webapp/dist` exists for the backend to serve,
+# then build the Rust binary.
+build: build-fe build-be
+
+build-fe:
+	cd webapp && npm install && npm run build
+
+build-be:
+	cargo build --release
+
+test: test-be test-fe
+
+test-be:
+	cargo test
+
+test-fe:
+	cd webapp && npm run build
+
+lint: lint-be lint-fe
+
+lint-be:
+	cargo clippy --all-targets
+
+lint-fe:
+	cd webapp && npm run lint
+
+# Run the built binary, serving the webapp from webapp/dist.
+run: build
+	./target/release/ottyl
+
+# Frontend dev server with hot reload (proxy API calls to a separately
+# running `cargo run` backend — see webapp/vite.config for the proxy setup).
+dev:
+	cd webapp && npm run dev
+
+clean:
+	cargo clean
+	rm -rf webapp/dist webapp/node_modules