fix(maestro): default the worktree toggle off when the directory is itself a worktree (#91)

Picking a project row that is itself a linked git worktree used to
default 'Create git worktree' on, so spawning asked for a second
worktree of an already-checked-out branch and git refused. Both clients
now default the toggle off there: the session just runs in that existing
worktree with no worktree record (not adoption). Turning it back on by
hand still tries, per the issue's non-goal.

web/src/spawnForm.ts

@@ -430,9 +430,19 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     cwdRawWrap.hidden = true;
     markActiveProject(project.path);
     // The scan already knows this directory is inside a repo (#61): the
-    // toggle defaults back on and no /api/gitroot round trip is needed.
-    wtEnabled.checked = true;
-    applyProjectRepo(project.base_repo ?? project.path);
+    // toggle defaults back on and no /api/gitroot round trip is needed —
+    // unless the directory *is* a linked worktree itself (#91): spawning
+    // in place is the only thing that works there, so default the toggle
+    // off. Turning it back on by hand still tries (and fails with git's
+    // own message), which is deliberate (#91 non-goal).
+    wtEnabled.checked = !project.is_worktree;
+    if (project.is_worktree) {
+      inferredBaseRepo = null;
+      wtBody.hidden = true;
+      wtHint.hidden = true;
+    } else {
+      applyProjectRepo(project.base_repo ?? project.path);
+    }
     emit();
     // Picking a project pre-selects the command it was last used with.
     const match = presets.find((p) => p.command === project.last_command && p.command !== "");