some changes

cht/agent/claude_sdk_provider.py

@@ -51,16 +51,36 @@ def _build_prompt(message: str, context: SessionContext) -> str:
     return "\n".join(lines)
 
 
+MODELS = [
+    "claude-sonnet-4-6",
+    "claude-opus-4-6",
+    "claude-haiku-4-5",
+]
+
+
 class ClaudeSDKProvider(AgentProvider):
     """Uses claude_agent_sdk — requires Claude Code CLI to be installed."""
 
-    def __init__(self, cwd: str | None = None, max_turns: int = 5):
+    def __init__(self, cwd: str | None = None, max_turns: int = 5, model: str = MODELS[0]):
         self._cwd = cwd
         self._max_turns = max_turns
+        self._model = model
 
     @property
     def name(self) -> str:
-        return "claude-code-sdk"
+        return f"claude-sdk/{self._model}"
+
+    @property
+    def available_models(self) -> list[str]:
+        return list(MODELS)
+
+    @property
+    def model(self) -> str:
+        return self._model
+
+    @model.setter
+    def model(self, value: str):
+        self._model = value
 
     def stream(self, message: str, context: SessionContext) -> Iterator[str]:
         prompt = _build_prompt(message, context)
@@ -70,6 +90,7 @@ class ClaudeSDKProvider(AgentProvider):
             async for msg in query(
                 prompt=prompt,
                 options=ClaudeAgentOptions(
+                    model=self._model,
                     cwd=self._cwd or str(context.session_dir),
                     allowed_tools=["Read"],
                     system_prompt=SYSTEM_PROMPT,