feat(argocd): recover Telegram notifications (failed/degraded) and prune for polymarket-bot

- Notifications via generic webhook to the Telegram Bot API: the engine's
  native telegram service only supports channels and negative group IDs,
  so a positive private chat_id never worked ("chat not found").
- Only on-sync-failed and on-health-degraded triggers; on-sync-succeeded
  dropped (CI already reports successful deploys).
- Subscribe annotations on polymarket-bot, researchowl and n8n.
- prune: true on polymarket-bot, guarded by Prune=false on the postgres
  PVC so removing the manifest from git can never destroy the data.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

argocd/application-n8n.yaml

@@ -3,6 +3,9 @@ kind: Application
 metadata:
   name: n8n
   namespace: argocd
+  annotations:
+    notifications.argoproj.io/subscribe.on-sync-failed.telegram: "5138407666"
+    notifications.argoproj.io/subscribe.on-health-degraded.telegram: "5138407666"
 spec:
   destination:
     namespace: n8n

argocd/application-polymarket-bot.yaml

@@ -3,6 +3,9 @@ kind: Application
 metadata:
   name: polymarket-bot
   namespace: argocd
+  annotations:
+    notifications.argoproj.io/subscribe.on-sync-failed.telegram: "5138407666"
+    notifications.argoproj.io/subscribe.on-health-degraded.telegram: "5138407666"
 spec:
   destination:
     namespace: polymarket-bot
@@ -14,4 +17,5 @@ spec:
     targetRevision: main
   syncPolicy:
     automated:
+      prune: true
       selfHeal: true

argocd/application-researchowl.yaml

@@ -5,6 +5,8 @@ metadata:
   namespace: argocd
   annotations:
     argocd.argoproj.io/tracking-id: researchowl:argoproj.io/Application:argocd/researchowl
+    notifications.argoproj.io/subscribe.on-sync-failed.telegram: "5138407666"
+    notifications.argoproj.io/subscribe.on-health-degraded.telegram: "5138407666"
 spec:
   destination:
     namespace: researchowl

argocd/configmap-argocd-notifications-cm.yaml

@@ -8,35 +8,36 @@ metadata:
   name: argocd-notifications-cm
   namespace: argocd
 data:
-  service.telegram: |
-    token: $telegram-token
-
-  template.app-sync-succeeded: |
-    telegram:
-      message: |
-        ✅ ArgoCD: {{.app.metadata.name}} sync completado
-        Revisión: {{.app.status.operationState.syncResult.revision | trunc 8}}
+  # The native telegram service of the notifications engine only supports
+  # channels (@name) and negative group chat IDs; a positive private chat ID
+  # like ours gets sent as "@<id>" and fails with "chat not found". Workaround:
+  # a generic webhook service against the Telegram Bot API, which accepts any
+  # chat_id. The service is still named "telegram" so the subscribe annotations
+  # read naturally.
+  service.webhook.telegram: |
+    url: https://api.telegram.org/bot$telegram-token/sendMessage
+    headers:
+      - name: Content-Type
+        value: application/json
 
   template.app-sync-failed: |
-    telegram:
-      message: |
-        ❌ ArgoCD: {{.app.metadata.name}} sync fallido
-        {{if .app.status.operationState.message}}Error: {{.app.status.operationState.message}}{{end}}
+    webhook:
+      telegram:
+        method: POST
+        body: |
+          {"chat_id": "5138407666", "text": {{toJson (printf "❌ ArgoCD: %s sync fallido\n%s" .app.metadata.name (or .app.status.operationState.message ""))}}}
 
   template.app-degraded: |
-    telegram:
-      message: |
-        ⚠️ ArgoCD: {{.app.metadata.name}} degradada
-        Health: {{.app.status.health.status}}
-
-  trigger.on-sync-succeeded: |
-    - when: app.status.operationState.phase in ['Succeeded']
-      send: [app-sync-succeeded]
+    webhook:
+      telegram:
+        method: POST
+        body: |
+          {"chat_id": "5138407666", "text": {{toJson (printf "⚠️ ArgoCD: %s degradada\nHealth: %s" .app.metadata.name .app.status.health.status)}}}
 
   trigger.on-sync-failed: |
-    - when: app.status.operationState.phase in ['Error', 'Failed']
+    - when: app.status.operationState != nil && app.status.operationState.phase in ['Error', 'Failed']
       send: [app-sync-failed]
 
-  trigger.on-degraded: |
+  trigger.on-health-degraded: |
     - when: app.status.health.status == 'Degraded'
       send: [app-degraded]