fix(gateway): remove _show_reasoning cache, always resolve per-platform config

Remove GatewayRunner._show_reasoning field that was initialized once at
startup using only global display.show_reasoning config. All consumers
now resolve show_reasoning per-platform via resolve_display_setting(),
ensuring display.platforms.<platform>.show_reasoning overrides work
correctly for all platforms (especially WeCom).

Changes:
- Delete self._show_reasoning initialization in __init__
- Update _handle_reasoning_command to resolve per-platform on each call
- Update reasoning_callback wiring to resolve per-platform
- Update response prepend logic to resolve per-platform
- Remove fallback to cached self._show_reasoning

Fixes: WeCom reasoning display respects per-platform config

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

gateway/run.py

@@ -624,7 +624,6 @@ class GatewayRunner:
         self._ephemeral_system_prompt = self._load_ephemeral_system_prompt()
         self._reasoning_config = self._load_reasoning_config()
         self._service_tier = self._load_service_tier()
-        self._show_reasoning = self._load_show_reasoning()
         self._busy_input_mode = self._load_busy_input_mode()
         self._restart_drain_timeout = self._load_restart_drain_timeout()
         self._provider_routing = self._load_provider_routing()
@@ -4401,10 +4400,10 @@ class GatewayRunner:
                     _load_gateway_config(),
                     _platform_config_key(source.platform),
                     "show_reasoning",
-                    getattr(self, "_show_reasoning", False),
+                    False,
                 )
             except Exception:
-                _show_reasoning_effective = getattr(self, "_show_reasoning", False)
+                _show_reasoning_effective = False
             if _show_reasoning_effective and response:
                 last_reasoning = agent_result.get("last_reasoning")
                 if last_reasoning:
@@ -6597,7 +6596,6 @@ class GatewayRunner:
         config_path = _hermes_home / "config.yaml"
         self._reasoning_config = self._load_reasoning_config()
         _pk = _platform_config_key(event.source.platform)
-        self._show_reasoning = self._load_show_reasoning(_pk)
 
         def _save_config_key(key_path: str, value):
             """Save a dot-separated key to config.yaml."""
@@ -6628,7 +6626,17 @@ class GatewayRunner:
                 level = "none (disabled)"
             else:
                 level = rc.get("effort", "medium")
-            display_state = "on ✓" if self._show_reasoning else "off"
+            try:
+                from gateway.display_config import resolve_display_setting as _rds
+                _show_reasoning = bool(_rds(
+                    _load_gateway_config(),
+                    _pk,
+                    "show_reasoning",
+                    False,
+                ))
+            except Exception:
+                _show_reasoning = False
+            display_state = "on ✓" if _show_reasoning else "off"
             return (
                 "🧠 **Reasoning Settings**\n\n"
                 f"**Effort:** `{level}`\n"
@@ -6639,7 +6647,6 @@ class GatewayRunner:
         # Display toggle (per-platform)
         platform_key = _platform_config_key(event.source.platform)
         if args in ("show", "on"):
-            self._show_reasoning = True
             _save_config_key(f"display.platforms.{platform_key}.show_reasoning", True)
             return (
                 "🧠 ✓ Reasoning display: **ON**\n"
@@ -6647,7 +6654,6 @@ class GatewayRunner:
             )
 
         if args in ("hide", "off"):
-            self._show_reasoning = False
             _save_config_key(f"display.platforms.{platform_key}.show_reasoning", False)
             return f"🧠 ✓ Reasoning display: **OFF** for **{platform_key}**"
 

tests/gateway/test_reasoning_command.py

@@ -33,7 +33,6 @@ def _make_runner():
     runner._ephemeral_system_prompt = ""
     runner._prefill_messages = []
     runner._reasoning_config = None
-    runner._show_reasoning = False
     runner._provider_routing = {}
     runner._fallback_model = None
     runner._running_agents = {}
@@ -90,14 +89,12 @@ class TestReasoningCommand:
 
         runner = _make_runner()
         runner._reasoning_config = {"enabled": True, "effort": "xhigh"}
-        runner._show_reasoning = False
 
         result = await runner._handle_reasoning_command(_make_event("/reasoning"))
 
         assert "**Effort:** `none (disabled)`" in result
         assert "**Display:** on ✓" in result
         assert runner._reasoning_config == {"enabled": False}
-        assert runner._show_reasoning is True
 
     @pytest.mark.asyncio
     async def test_load_show_reasoning_resolves_per_platform(self, tmp_path, monkeypatch):