Bootstrap configuration loading (#46)

crates/arr-daemon/src/main.rs

@@ -1,5 +1,18 @@
 //! arr — reconcile loop and process entry point. See DESIGN.md §8.
 
-fn main() {
-    println!("arr");
+mod config;
+
+use std::process::ExitCode;
+
+fn main() -> ExitCode {
+    match config::Config::load() {
+        Ok(config) => {
+            println!("arr starting, bind_addr={}", config.bind_addr);
+            ExitCode::SUCCESS
+        }
+        Err(err) => {
+            eprintln!("arr: {err}");
+            ExitCode::FAILURE
+        }
+    }
 }