FIX: Discord notifikace se od začátku tiše zahazovaly — bot REST fallback

Všechny site webhook URL jsou NULL a env DISCORD_WEBHOOK_URL nebyl nastaven
→ send_discord vždy skončil na 'not configured, skipping' (uživatel: 'nikdy
mi nic nepřišlo'). Fix: fallback přes bota (REST POST do DISCORD_EV_CHANNEL_ID
— token už v .env, žádný webhook netřeba); webhook má přednost, kdyby ho
uživatel později nastavil per site. Bot navíc při startu pošle '✅ online'
(viditelný důkaz, 1× per deploy).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/services/discord_bot.py

@@ -193,6 +193,13 @@ async def run_discord_bot() -> None:
     @client.event
     async def on_ready() -> None:
         logger.info("Discord bot připojen jako %s", client.user)
+        try:
+            channel_id = int(getattr(get_settings(), "discord_ev_channel_id", 0) or 0)
+            ch = client.get_channel(channel_id) if channel_id else None
+            if ch is not None:
+                await ch.send("✅ EMS bot online — notifikace aktivní")
+        except Exception:
+            logger.exception("Discord on_ready ping failed")
 
     @client.event
     async def on_interaction(interaction: discord.Interaction) -> None:

backend/services/notification_service.py

@@ -195,24 +195,41 @@ async def send_discord(
     """
     kind = "daily" if level == "info" else "error"
     webhook_url = await _get_site_webhook_url(conn, site_id, kind)
-    if not webhook_url:
-        logger.debug("Discord webhook not configured, skipping notification")
-        return False
-
     emoji = {"info": "ℹ️", "warning": "⚠️", "error": "❌", "critical": "🚨"}.get(level, "ℹ️")
+    content = f"{emoji} **EMS** [{level.upper()}]\n{message}"
 
+    if webhook_url:
+        try:
+            async with httpx.AsyncClient(timeout=10) as client:
+                resp = await client.post(webhook_url, json={"content": content})
+                resp.raise_for_status()
+                return True
+        except Exception as e:
+            logger.warning("Discord webhook failed: %s — zkouším bot fallback", e)
+
+    # Fallback: bot REST (kanál z DISCORD_EV_CHANNEL_ID) — webhooky per site
+    # nebyly nikdy nastavené, takže bez fallbacku se notifikace tiše zahazovaly.
+    return await _send_via_bot(content)
+
+
+async def _send_via_bot(content: str) -> bool:
+    s = get_settings()
+    token = (getattr(s, "discord_bot_token", "") or "").strip()
+    channel = (getattr(s, "discord_ev_channel_id", "") or "").strip()
+    if not token or not channel:
+        logger.debug("Discord: žádný webhook ani bot — notifikace zahozena")
+        return False
     try:
         async with httpx.AsyncClient(timeout=10) as client:
-            resp = await client.post(
-                webhook_url,
-                json={
-                    "content": f"{emoji} **EMS Alert** [{level.upper()}]\n{message}",
-                },
+            r = await client.post(
+                f"https://discord.com/api/v10/channels/{channel}/messages",
+                headers={"Authorization": f"Bot {token}"},
+                json={"content": content[:1900]},
             )
-            resp.raise_for_status()
+            r.raise_for_status()
             return True
     except Exception as e:
-        logger.warning("Discord notification failed: %s", e)
+        logger.warning("Discord bot fallback failed: %s", e)
         return False