fix: remove redundant key normalization and defensive getattr in channel_prompts

- Remove double str() normalization in _resolve_channel_prompt since
  config bridging already handles numeric YAML key conversion
- Remove dead prompts.get(str(key)) fallback that could never match
  after keys were already normalized to strings
- Replace getattr(event, "channel_prompt", None) with direct attribute
  access since channel_prompt is a declared dataclass field
- Update test to verify normalization responsibility lives in config bridging

gateway/platforms/discord.py

@@ -2122,14 +2122,11 @@ class DiscordAdapter(BasePlatformAdapter):
         prompts = self.config.extra.get("channel_prompts") or {}
         if not isinstance(prompts, dict):
             return None
-        prompts = {str(k): v for k, v in prompts.items()}
 
         for key in (channel_id, parent_id):
             if not key:
                 continue
             prompt = prompts.get(key)
-            if prompt is None:
-                prompt = prompts.get(str(key))
             if prompt is None:
                 continue
             prompt = str(prompt).strip()

gateway/run.py

@@ -2891,7 +2891,7 @@ class GatewayRunner:
                         message_type=_MT.TEXT,
                         source=event.source,
                         message_id=event.message_id,
-                        channel_prompt=getattr(event, "channel_prompt", None),
+                        channel_prompt=event.channel_prompt,
                     )
                     adapter._pending_messages[_quick_key] = queued_event
                 return "Queued for the next turn."
@@ -3869,7 +3869,7 @@ class GatewayRunner:
                 session_id=session_entry.session_id,
                 session_key=session_key,
                 event_message_id=event.message_id,
-                channel_prompt=getattr(event, "channel_prompt", None),
+                channel_prompt=event.channel_prompt,
             )
 
             # Stop persistent typing indicator now that the agent is done
@@ -5091,7 +5091,7 @@ class GatewayRunner:
             message_type=MessageType.TEXT,
             source=source,
             raw_message=event.raw_message,
-            channel_prompt=getattr(event, "channel_prompt", None),
+            channel_prompt=event.channel_prompt,
         )
         
         # Let the normal message handler process it
@@ -9384,7 +9384,7 @@ class GatewayRunner:
                     session_key=session_key,
                     _interrupt_depth=_interrupt_depth + 1,
                     event_message_id=next_message_id,
-                    channel_prompt=getattr(pending_event, "channel_prompt", None),
+                    channel_prompt=pending_event.channel_prompt,
                 )
         finally:
             # Stop progress sender, interrupt monitor, and notification task

tests/gateway/test_discord_channel_prompts.py

@@ -91,10 +91,19 @@ class TestResolveChannelPrompts:
         adapter.config.extra = {"channel_prompts": {"100": "Research mode"}}
         assert adapter._resolve_channel_prompt("100") == "Research mode"
 
-    def test_match_by_numeric_channel_id_key(self):
+    def test_numeric_yaml_keys_normalized_at_config_load(self):
+        """Numeric YAML keys are normalized to strings by config bridging.
+
+        The resolver itself expects string keys (config.py handles normalization),
+        so raw numeric keys will not match — this is intentional.
+        """
         adapter = _make_adapter()
-        adapter.config.extra = {"channel_prompts": {100: "Research mode"}}
+        # Simulates post-bridging state: keys are already strings
+        adapter.config.extra = {"channel_prompts": {"100": "Research mode"}}
         assert adapter._resolve_channel_prompt("100") == "Research mode"
+        # Pre-bridging numeric key would not match (bridging is responsible)
+        adapter.config.extra = {"channel_prompts": {100: "Research mode"}}
+        assert adapter._resolve_channel_prompt("100") is None
 
     def test_match_by_parent_id(self):
         adapter = _make_adapter()