fix(build): align lint target and .dockerignore with CI/gitignore

- Makefile lint target now runs `cargo clippy --workspace` to match
  what CI actually runs (.github/workflows/ci.yml), previously it
  only linted the root crate.
- .dockerignore was missing `artifacts/`, which is already excluded
  via .gitignore and was explicitly called out in issue #922.

Author: Markodiba

.dockerignore

@@ -9,6 +9,7 @@ benches/src/scrap-menu/
 
 # Rust build artifacts
 *.wasm
+artifacts/
 
 # Logs
 *.log

Makefile

@@ -7,7 +7,7 @@ test-all:
 	cargo test --workspace
 
 lint:
-	cargo clippy -- -D warnings
+	cargo clippy --workspace -- -D warnings
 
 build-wasm:
 	cargo build --target wasm32-unknown-unknown --release