Remove dashboard-load timing instrumentation

The perf logs were temporary diagnostics used to identify that slow
reloads were caused by a registered remote node timing out in
/projects/across-nodes. Root cause is resolved and the short-circuit
for zero-remote setups (already committed in 7ea60382a) remains.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/core/src/__tests__/agent-instructions-bundle.test.ts

@@ -27,9 +27,11 @@ describe("AgentStore — instructions bundle", () => {
     }
     createdAgentIds.length = 0;
 
+    store.close();
+
     // Filesystem cleanup last
     try {
-      await rm(testDir, { recursive: true, force: true });
+      await rm(testDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 });
     } catch {
       // Ignore cleanup errors
     }

packages/core/src/__tests__/agent-instructions.test.ts

@@ -27,9 +27,11 @@ describe("AgentStore — instructions fields", () => {
     }
     createdAgentIds.length = 0;
 
+    store.close();
+
     // Filesystem cleanup last
     try {
-      await rm(testDir, { recursive: true, force: true });
+      await rm(testDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 });
     } catch {
       // Ignore cleanup errors
     }