fix: add missing JobContext fields and resolve fmt/clippy warnings

Add total_tokens_used and max_tokens fields to JobContext in
libsql_backend.rs, apply cargo fmt, and fix clippy warnings.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

src/workspace/mod.rs

@@ -433,7 +433,9 @@ impl Workspace {
 
     /// List all files recursively (flat list of all paths).
     pub async fn list_all(&self) -> Result<Vec<String>, WorkspaceError> {
-        self.storage.list_all_paths(&self.user_id, self.agent_id).await
+        self.storage
+            .list_all_paths(&self.user_id, self.agent_id)
+            .await
     }
 
     // ==================== Convenience Methods ====================