fix(kimi): send max_tokens, reasoning_effort, and thinking for Kimi/Moonshot

Kimi/Moonshot endpoints require explicit parameters that Hermes was not
sending, causing 'Response truncated due to output length limit' errors
and inconsistent reasoning behavior.

Root cause analysis against Kimi CLI source (MoonshotAI/kimi-cli,
packages/kosong/src/kosong/chat_provider/kimi.py):

1. max_tokens: Kimi's API defaults to a very low value when omitted.
   Reasoning tokens share the output budget — the model exhausts it on
   thinking alone.  Send 32000, matching Kimi CLI's generate() default.

2. reasoning_effort: Kimi CLI sends this as a top-level parameter (not
   inside extra_body).  Hermes was not sending it at all because
   _supports_reasoning_extra_body() returns False for non-OpenRouter
   endpoints.

3. extra_body.thinking: Kimi CLI uses with_thinking() which sets
   extra_body.thinking={"type":"enabled"} alongside reasoning_effort.
   This is a separate control from the OpenAI-style reasoning extra_body
   that Hermes sends for OpenRouter/GitHub.  Without it, the Kimi gateway
   may not activate reasoning mode correctly.

Covers api.kimi.com (Kimi Code) and api.moonshot.ai/cn (Moonshot).

Tests: 6 new test cases for max_tokens, reasoning_effort, and
extra_body.thinking under various configs.

run_agent.py

@@ -6909,6 +6909,34 @@ class AIAgent:
             # (the documented max output for qwen3-coder models) so the
             # model has adequate output budget for tool calls.
             api_kwargs.update(self._max_tokens_param(65536))
+        elif (
+            base_url_host_matches(self.base_url, "api.kimi.com")
+            or base_url_host_matches(self.base_url, "moonshot.ai")
+            or base_url_host_matches(self.base_url, "moonshot.cn")
+        ):
+            # Kimi/Moonshot defaults to a low max_tokens when omitted.
+            # Reasoning tokens share the output budget — without an explicit
+            # value the model can exhaust it on thinking alone, causing
+            # "Response truncated due to output length limit".  32000 matches
+            # Kimi CLI's default (see MoonshotAI/kimi-cli kimi.py generate()).
+            api_kwargs.update(self._max_tokens_param(32000))
+            # Kimi requires reasoning_effort as a top-level chat completions
+            # parameter (not inside extra_body).  Mirror Kimi CLI's
+            # with_generation_kwargs(reasoning_effort=...) / with_thinking():
+            # when thinking is disabled, Kimi CLI omits reasoning_effort
+            # entirely (maps to None).
+            _kimi_thinking_off = bool(
+                self.reasoning_config
+                and isinstance(self.reasoning_config, dict)
+                and self.reasoning_config.get("enabled") is False
+            )
+            if not _kimi_thinking_off:
+                _kimi_effort = "medium"
+                if self.reasoning_config and isinstance(self.reasoning_config, dict):
+                    _e = (self.reasoning_config.get("effort") or "").strip().lower()
+                    if _e in ("low", "medium", "high"):
+                        _kimi_effort = _e
+                api_kwargs["reasoning_effort"] = _kimi_effort
         elif (self._is_openrouter_url() or "nousresearch" in self._base_url_lower) and "claude" in (self.model or "").lower():
             # OpenRouter and Nous Portal translate requests to Anthropic's
             # Messages API, which requires max_tokens as a mandatory field.
@@ -6940,6 +6968,24 @@ class AIAgent:
             extra_body["provider"] = provider_preferences
         _is_nous = "nousresearch" in self._base_url_lower
 
+        # Kimi/Moonshot API uses extra_body.thinking (separate from the
+        # top-level reasoning_effort) to enable/disable reasoning mode.
+        # Mirror Kimi CLI's with_thinking() behavior exactly — see
+        # MoonshotAI/kimi-cli packages/kosong/src/kosong/chat_provider/kimi.py
+        _is_kimi = (
+            base_url_host_matches(self.base_url, "api.kimi.com")
+            or base_url_host_matches(self.base_url, "moonshot.ai")
+            or base_url_host_matches(self.base_url, "moonshot.cn")
+        )
+        if _is_kimi:
+            _kimi_thinking_enabled = True
+            if self.reasoning_config and isinstance(self.reasoning_config, dict):
+                if self.reasoning_config.get("enabled") is False:
+                    _kimi_thinking_enabled = False
+            extra_body["thinking"] = {
+                "type": "enabled" if _kimi_thinking_enabled else "disabled",
+            }
+
         if self._supports_reasoning_extra_body():
             if _is_github_models:
                 github_reasoning = self._github_models_reasoning_extra_body()