fix(cli): improve command conflict handling for skills

- Prioritize built-in commands in slashCommandProcessor to ensure they retain their intended names.
- Add extensionName to SkillDefinition to track source extensions.
- Update ExtensionManager to tag loaded skills with their source extension name.
- Update SlashCommandResolver and SlashCommandConflictHandler to properly handle and describe conflicts involving skills.
- Skill conflicts from extensions now produce clear notifications like "Extension 'google-workspace' skill '/chat' was renamed to '/google-workspace.chat'" instead of generic "Existing command" messages.

Fixes built-in command rename issues observed on startup.

packages/core/src/code_assist/oauth2.test.ts

@@ -480,6 +480,7 @@ describe('oauth2', () => {
       expect(fs.existsSync(googleAccountPath)).toBe(true);
       if (fs.existsSync(googleAccountPath)) {
         const cachedGoogleAccount = fs.readFileSync(googleAccountPath, 'utf-8');
+
         expect(JSON.parse(cachedGoogleAccount)).toEqual({
           active: 'test-user-code-account@gmail.com',
           old: [],
@@ -1349,7 +1350,7 @@ describe('oauth2', () => {
         let dataHandler: ((data: Buffer) => void) | undefined;
         await vi.waitFor(() => {
           const dataCall = stdinOnSpy.mock.calls.find(
-            (call: [string, ...unknown[]]) => call[0] === 'data',
+            (call: [string | symbol, ...unknown[]]) => call[0] === 'data',
           );
           dataHandler = dataCall?.[1] as ((data: Buffer) => void) | undefined;
           if (!dataHandler) throw new Error('stdin handler not registered yet');

packages/core/src/skills/skillLoader.ts

@@ -27,6 +27,8 @@ export interface SkillDefinition {
   disabled?: boolean;
   /** Whether the skill is a built-in skill. */
   isBuiltin?: boolean;
+  /** The name of the extension that provided this skill, if any. */
+  extensionName?: string;
 }
 
 export const FRONTMATTER_REGEX =

packages/core/src/telemetry/memory-monitor.test.ts

@@ -89,6 +89,7 @@ const mockHeapStatistics = {
   total_global_handles_size: 8192,
   used_global_handles_size: 4096,
   external_memory: 2097152,
+  total_allocated_bytes: 31457280,
 };
 
 const mockHeapSpaceStatistics = [