feat(discord): split decisions/news into second webhook channel

Adds DISCORD_WEBHOOK_DECISIONS_URL env var. If set, decision and
news_alert posts go to that channel; all other events stay on the
main webhook. Falls back to main webhook if not configured.

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

src/aitrader/config.py

@@ -87,6 +87,7 @@ class Settings(BaseModel):
     openrouter_api_key: str = ""
     cryptopanic_api_key: str = ""
     discord_webhook_url: str = ""
+    discord_webhook_decisions_url: str = ""
     db_path: str = "data/aitrader.db"
 
 
@@ -113,6 +114,7 @@ def get_settings() -> Settings:
         openrouter_api_key=os.getenv("OPENROUTER_API_KEY", ""),
         cryptopanic_api_key=os.getenv("CRYPTOPANIC_API_KEY", ""),
         discord_webhook_url=os.getenv("DISCORD_WEBHOOK_URL", ""),
+        discord_webhook_decisions_url=os.getenv("DISCORD_WEBHOOK_DECISIONS_URL", ""),
         db_path=os.getenv("AITRADER_DB", "data/aitrader.db"),
     )
     return settings

src/aitrader/notify/discord.py

@@ -22,16 +22,16 @@ def _enabled(settings: Settings) -> bool:
     return bool(settings.discord.enabled and settings.discord_webhook_url)
 
 
-def _post(settings: Settings, embed: dict[str, Any]) -> None:
+def _post(settings: Settings, embed: dict[str, Any], channel: str = "trades") -> None:
     if not _enabled(settings):
         return
+    if channel == "decisions" and settings.discord_webhook_decisions_url:
+        url = settings.discord_webhook_decisions_url
+    else:
+        url = settings.discord_webhook_url
     embed.setdefault("timestamp", datetime.now(timezone.utc).isoformat())
     try:
-        r = requests.post(
-            settings.discord_webhook_url,
-            json={"embeds": [embed]},
-            timeout=8,
-        )
+        r = requests.post(url, json={"embeds": [embed]}, timeout=8)
         if r.status_code >= 400:
             log.warning("discord.post_failed", status=r.status_code, body=r.text[:200])
     except requests.RequestException as e:
@@ -88,6 +88,7 @@ def notify_decision(settings: Settings, symbol: str, ensemble, label_a: str, lab
                 {"name": "Rationale", "value": ensemble.rationale, "inline": False},
             ],
         },
+        channel="decisions",
     )
 
 
@@ -227,4 +228,5 @@ def notify_news_alert(settings: Settings, symbol: str, headlines: list[dict[str,
             "color": color,
             "description": top,
         },
+        channel="decisions",
     )