fix: resolve model aliases before syntax validation

Fixes alias resolution ordering: aliases (opus/sonnet/haiku) are now resolved to their full provider/model form BEFORE syntax validation. Previously, aliases bypassed validation via an early-return check. Also adds the 'log' crate for debug tracing of alias resolution and wraps PermissionsExt import in #[cfg(unix)] for portability.

rust/crates/rusty-claude-cli/Cargo.toml

@@ -23,6 +23,8 @@ serde_json.workspace = true
 syntect = "5"
 tokio = { version = "1", features = ["rt-multi-thread", "signal", "time"] }
 tools = { path = "../tools" }
+log = "0.4"
+
 
 [lints]
 workspace = true