feat(ai): support stdin for Gemini CLI and verify with integration test

gemini_cli_adapter.py

@@ -12,25 +12,36 @@ class GeminiCliAdapter:
         """
         Sends a message to the Gemini CLI and processes the streaming JSON output.
         """
-        command = [self.binary_path, 'run', message, '--output-format', 'stream-json']
+        # On Windows, using shell=True allows executing .cmd/.bat files and 
+        # handles command strings with arguments more gracefully.
+        # We pass the message via stdin to avoid command-line length limits.
+        command = f'{self.binary_path} run --output-format stream-json'
         if self.session_id:
-            command.extend(['--resume', self.session_id])
+            command += f' --resume {self.session_id}'
 
+        print(f"[DEBUG] GeminiCliAdapter: Executing command: {command}")
         accumulated_text = ""
         
-        # Using subprocess.Popen as requested
         process = subprocess.Popen(
             command,
+            stdin=subprocess.PIPE,
             stdout=subprocess.PIPE,
-            text=True
+            stderr=subprocess.PIPE,
+            text=True,
+            shell=True
         )
 
         try:
+            # Send message to stdin and close it
+            process.stdin.write(message)
+            process.stdin.close()
+
             # Read stdout line by line
             for line in process.stdout:
                 line = line.strip()
                 if not line:
                     continue
+                print(f"[DEBUG] GeminiCliAdapter stdout: {line}")
 
                 try:
                     data = json.loads(line)
@@ -55,8 +66,12 @@ class GeminiCliAdapter:
                     continue
 
             process.wait()
+            if process.returncode != 0:
+                err = process.stderr.read()
+                print(f"[DEBUG] GeminiCliAdapter failed with exit code {process.returncode}. stderr: {err}")
         except Exception as e:
             process.kill()
+            print(f"[DEBUG] GeminiCliAdapter exception: {e}")
             raise e
 
         return accumulated_text