feat: completions update, create promptrequest, LLM flag rename, ACP content fix

- Add prompts/promptrequests to shell completions (fish + bash)
- Add approve, setup, prompt, promptrequest commands to completions
- Add `create promptrequest` CLI command (POST /projects/:name/promptrequests)
- Rename --proxy-mode-llm-provider/model to --llm-provider/model
- Fix ACP client: handle single-object content format from real Gemini
- Add tests for single-object content and agent_thought_chunk filtering

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/mcplocal/tests/acp-client.test.ts

@@ -230,6 +230,77 @@ describe('AcpClient', () => {
       expect(result).toBe('Part A Part B');
     });
 
+    it('handles single-object content (real Gemini ACP format)', async () => {
+      createClient();
+      autoHandshake('sess-1');
+      await client.ensureReady();
+
+      mock.stdin.write.mockImplementation((data: string) => {
+        const msg = JSON.parse(data.trim()) as { id: number; method: string };
+        if (msg.method === 'session/prompt') {
+          setImmediate(() => {
+            // Real Gemini ACP sends content as a single object, not an array
+            mock.sendLine({
+              jsonrpc: '2.0',
+              method: 'session/update',
+              params: {
+                sessionId: 'sess-1',
+                update: {
+                  sessionUpdate: 'agent_message_chunk',
+                  content: { type: 'text', text: 'ok' },
+                },
+              },
+            });
+            mock.sendResponse(msg.id, { stopReason: 'end_turn' });
+          });
+        }
+      });
+
+      const result = await client.prompt('test');
+      expect(result).toBe('ok');
+    });
+
+    it('ignores agent_thought_chunk notifications', async () => {
+      createClient();
+      autoHandshake('sess-1');
+      await client.ensureReady();
+
+      mock.stdin.write.mockImplementation((data: string) => {
+        const msg = JSON.parse(data.trim()) as { id: number; method: string };
+        if (msg.method === 'session/prompt') {
+          setImmediate(() => {
+            // Gemini sends thought chunks before message chunks
+            mock.sendLine({
+              jsonrpc: '2.0',
+              method: 'session/update',
+              params: {
+                sessionId: 'sess-1',
+                update: {
+                  sessionUpdate: 'agent_thought_chunk',
+                  content: { type: 'text', text: 'Thinking about it...' },
+                },
+              },
+            });
+            mock.sendLine({
+              jsonrpc: '2.0',
+              method: 'session/update',
+              params: {
+                sessionId: 'sess-1',
+                update: {
+                  sessionUpdate: 'agent_message_chunk',
+                  content: { type: 'text', text: 'ok' },
+                },
+              },
+            });
+            mock.sendResponse(msg.id, { stopReason: 'end_turn' });
+          });
+        }
+      });
+
+      const result = await client.prompt('test');
+      expect(result).toBe('ok');
+    });
+
     it('calls ensureReady automatically (lazy init)', async () => {
       createClient();
       autoHandshake('sess-auto');