test(maestro): update collision tests for branch suffixing

49ab7e9 made a new-branch worktree add suffix the branch name instead of
failing, and documented it, but left two tests asserting the old hard
rejection. The rejection contract (#66) still holds for an existing
branch that is already checked out, so that test now exercises that
case.

crates/maestro-daemon/tests/worktree.rs

@@ -405,8 +405,10 @@ fn run_git(dir: &std::path::Path, args: &[&str]) {
     );
 }
 
+/// 49ab7e9: a new-branch add onto a name that already exists suffixes the
+/// branch (and so the directory) instead of failing, per docs/WORKTREES.md.
 #[test]
-fn add_fails_when_branch_already_exists() {
+fn add_new_suffixes_when_branch_already_exists() {
     let repo_dir = TempDir::new().unwrap();
     let repo = repo_dir.path().to_path_buf();
     init_repo(&repo);
@@ -423,9 +425,9 @@ fn add_fails_when_branch_already_exists() {
     let wt_root = TempDir::new().unwrap();
     let mgr = WorktreeManager::new(Some(wt_root.path().to_path_buf()));
 
-    let err = mgr.add_new(&repo, "feat/dup").unwrap_err();
-    let msg = format!("{err}");
-    assert!(msg.contains("git exited"), "{msg}");
+    let path = mgr.add_new(&repo, "feat/dup").unwrap();
+    assert!(path.ends_with("feat/dup-2"), "{}", path.display());
+    assert!(path.is_dir());
 }
 
 /// The project picker lists linked worktrees as pickable rows, so `base_repo`

crates/maestro-e2e/tests/e2e.rs

@@ -328,8 +328,11 @@ async fn spawn_new_branch_creates_worktree_and_runs_in_it() {
     client.kill_session(s.id).await.expect("kill");
 }
 
-/// #66: a second spawn onto a branch that already has a worktree is rejected
-/// with a structured worktree error; the first worktree stays intact.
+/// #66: a second spawn onto an *existing* branch that already has a worktree
+/// is rejected with a structured worktree error; the first worktree stays
+/// intact. (A second `create_branch: true` spawn is a different case: 49ab7e9
+/// suffixes the new branch name instead, see
+/// `colliding_branch_name_gets_suffixed_too`.)
 #[tokio::test(flavor = "multi_thread")]
 async fn second_spawn_on_same_branch_is_rejected() {
     let (_daemon, client) = bring_up().await;
@@ -342,7 +345,7 @@ async fn second_spawn_on_same_branch_is_rejected() {
         .await
         .expect("first spawn");
     let dup = client
-        .spawn_session(&worktree_req(base.path(), "feature/dup", true))
+        .spawn_session(&worktree_req(base.path(), "feature/dup", false))
         .await;
     match dup {
         Err(maestro_e2e::ClientError::Api(maestro_protocol::ClientError::Api { info, .. })) => {