fix(#4662): clear workspace skeleton on switch-failure no-workspace path

The success path clears a stranded workspace-tree skeleton when the new
profile has no bound workspace (both switch branches), but the catch block
only restored the tree `if (S.session && S.session.workspace)` — with no
else. So a profile-switch failure while the workspace panel is open and the
(still-current) previous session has no workspace left the up-front skeleton
shimmering forever: the same skeleton-strand class the Codex/Opus gates
targeted, in the one path they didn't cover. Mirror the success-path
no-workspace handling in the failure path. Adds a static regression
assertion that the catch block clears the workspace skeleton.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

static/panels.js

@@ -6113,6 +6113,11 @@ async function switchToProfile(name) {
       }
       if (_workspaceVisibleAtStart && S.session && S.session.workspace && typeof loadDir === 'function') {
         loadDir('.');
+      } else if (_workspaceVisibleAtStart && typeof clearWorkspaceTreeSkeleton === 'function') {
+        // No workspace to restore on the (still-current) previous profile —
+        // clear the up-front workspace skeleton so it doesn't strand on a switch
+        // failure, mirroring the success-path no-workspace handling (#4662).
+        clearWorkspaceTreeSkeleton();
       }
     }
   } finally {

tests/test_issue4662_profile_switch_skeleton_static.py

@@ -58,6 +58,17 @@ class TestSwitchWiring:
         catch = body[body.index("} catch (e) {"):]
         assert "renderSessionListFromCache()" in catch, "failed switch must restore real list"
 
+    def test_failure_path_clears_workspace_skeleton_when_no_workspace(self):
+        # The success path clears a stranded workspace skeleton when the profile
+        # has no bound workspace; the failure path must do the same — otherwise a
+        # switch failure while the workspace panel is open and the (still-current)
+        # session has no workspace strands the up-front skeleton forever (#4662).
+        body = _switch_body()
+        catch = body[body.index("} catch (e) {"):]
+        assert "clearWorkspaceTreeSkeleton()" in catch, (
+            "failed switch must clear the workspace skeleton when there's no workspace to restore"
+        )
+
     def test_noop_self_switch_early_returns(self):
         # Opus gate #4662: a switch to the already-active profile must bail before
         # showing a skeleton (activateCurrentProfile() doesn't pre-check), else it