fix(agents): Compare a local-checkout task's changes against the current HEAD

Commits made in the project while a local task runs no longer show up in
its Changes pane, and Refresh lists what is actually uncommitted.

crates/ide-agent/src/lib.rs

@@ -577,7 +577,13 @@ impl Task {
 
     fn cwd_and_base(&self) -> (PathBuf, String) {
         let s = self.state.lock();
-        (s.task.cwd.0.clone(), s.task.base_commit.clone().unwrap_or_else(|| "HEAD".into()))
+        // In the project's own checkout the user commits too: compare against the current HEAD,
+        // as the Commit tool window does, so commits made since the task started drop out.
+        let base = match s.task.isolation {
+            Isolation::Local => None,
+            Isolation::Worktree => s.task.base_commit.clone(),
+        };
+        (s.task.cwd.0.clone(), base.unwrap_or_else(|| "HEAD".into()))
     }
 
     fn emit_task(&self) {

crates/ide-agent/src/model.rs

@@ -44,7 +44,7 @@ pub struct AgentTask {
     pub branch: Option<String>,
     /// Branch (or revision) the worktree was created from.
     pub base: Option<String>,
-    /// Commit the task's changes are compared against.
+    /// Commit the task's changes are compared against (worktree tasks; local ones use `HEAD`).
     pub base_commit: Option<String>,
     /// Why the task failed, when it did.
     pub error: Option<String>,