test(native-chat): use an agent without chat modes in the paired-host permission tests (#29891)

#29335 gave Grok chats their own permission modes, so on a paired host
that predates per-chat modes a Grok chat is now checked like Claude and
Codex; that is intended. #29442's tests, merged a day earlier, used Grok
as the agent without modes. Use Gemini, which still has none.

src/renderer/src/runtime/structured-chat-host-permission.test.ts

@@ -104,9 +104,10 @@ describe('the permission verdict on a paired host', () => {
     await expect(
       readStructuredChatHostPermissionVerdict({ kind: 'local' }, 'claude', 'ask')
     ).resolves.toEqual({ kind: 'allowed' })
-    await expect(readStructuredChatHostPermissionVerdict(PAIRED, 'grok', 'ask')).resolves.toEqual({
-      kind: 'allowed'
-    })
+    // Gemini chats have no modes of their own; Grok gained them in #29335.
+    await expect(readStructuredChatHostPermissionVerdict(PAIRED, 'gemini', 'ask')).resolves.toEqual(
+      { kind: 'allowed' }
+    )
     expect(mocks.supportsCapability).not.toHaveBeenCalled()
     expect(mocks.callRuntimeRpc).not.toHaveBeenCalled()
   })

src/shared/agent-chat-permission-host-support.test.ts

@@ -29,7 +29,8 @@ describe('what a host predating per-chat modes runs', () => {
   })
 
   it('names no mode for an agent without chat modes', () => {
-    expect(legacyHostChatPermissionMode('grok', {})).toBeNull()
+    // Grok gained chat modes in #29335; Gemini still has none.
+    expect(legacyHostChatPermissionMode('gemini', {})).toBeNull()
   })
 })