Implement CLI argument parsing with clap and config file loading

- Add Cli struct with clap derive macros for --config, --validate, --allow-wildcard-bind flags
- Config loading: reads TOML, deserializes into StaticConfig + DynamicConfig, validates
- --validate: load, validate, print success/errors, exit 0 or 1
- --allow-wildcard-bind is OR'd with config allow_wildcard_bind field
- Default config path: /etc/reverse-proxy/config.toml
- Version from Cargo.toml via clap
- Unit tests for CLI argument parsing and config loading
- Integration tests for --validate with valid/invalid config and --allow-wildcard-bind

src/main.rs

@@ -1,3 +1,22 @@
+use reverse_proxy::cli;
+
 fn main() {
-    tracing::info!("reverse-proxy starting");
+    let args = cli::parse();
+
+    if args.validate {
+        match cli::run_validate(&args) {
+            Ok(()) => std::process::exit(0),
+            Err(_) => std::process::exit(1),
+        }
+    }
+
+    match cli::load_config(&args) {
+        Ok(_config) => {
+            tracing::info!("reverse-proxy starting");
+        }
+        Err(e) => {
+            eprintln!("error: {e:#}");
+            std::process::exit(1);
+        }
+    }
 }