ci: add comprehensive formatting and linting setup

- Add formatting commands to justfile (format, fmt_check, clippy_check, fc)
- Create GitHub Actions workflows for automated fmt and clippy checks
- Fix existing clippy warnings in macro code
- Ensure CI enforcement of code quality standards

This brings native_model in line with native_db's robust formatting and linting approach.

libraries/native_model/justfile

@@ -60,3 +60,20 @@ bench_overhead:
     cargo bench --bench overhead
 
 bench_all: bench_overhead
+
+format:
+    cargo clippy; \
+    cargo fmt --all
+
+fmt_check:
+    cargo fmt --all -- --check
+
+clippy_check:
+    rustc --version; \
+    cargo clippy --version; \
+    cargo clippy -- -D warnings
+
+# Format check
+fc:
+    just fmt_check; \
+    just clippy_check