Owner notification webhook: Telegram re-point (#23)

Flask fires a fire-and-forget internal webhook (owner_notify.py, mirroring
mailer.py's background-thread queue) on booking create/cancel/reschedule,
carrying the same {booking, business_name, notify_channel} shape the old
EA-driven "Build booking row" node produced, plus an event field so the
Telegram message can say what actually happened. n8n/booking-sync.json gets
a new webhook + IF node feeding the existing Telegram node directly, so it
no longer needs EA's API to build the notification payload; channel routing
(only telegram sends for now) lives in that IF node.

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

n8n/booking-sync.json

@@ -68,7 +68,7 @@
         "resource": "message",
         "operation": "sendMessage",
         "chatId": "5499280257",
-        "text": "=📅 Neue Buchung\nBetrieb: {{ $('Build booking row').item.json.business_name || $('Build booking row').item.json.booking.client_id }}\nKunde: {{ $('Build booking row').item.json.booking.customer_name || '—' }}\nLeistung: {{ $('Build booking row').item.json.booking.service || '—' }}\nWann: {{ $('Build booking row').item.json.booking.start_time || '—' }}\nKontakt: {{ $('Build booking row').item.json.booking.customer_contact || '—' }}\nQuelle: {{ $('Build booking row').item.json.booking.source }}",
+        "text": "=📅 {{ $json.body.event === 'cancelled' ? 'Buchung storniert' : $json.body.event === 'rescheduled' ? 'Buchung verschoben' : 'Neue Buchung' }}\nBetrieb: {{ $json.body.business_name || $json.body.booking.client_id }}\nKunde: {{ $json.body.booking.customer_name || '—' }}\nLeistung: {{ $json.body.booking.service || '—' }}\nWann: {{ $json.body.booking.start_time || '—' }}\nKontakt: {{ $json.body.booking.customer_contact || '—' }}\nQuelle: {{ $json.body.booking.source }}",
         "additionalFields": {
           "appendAttribution": false
         }
@@ -79,7 +79,7 @@
       "typeVersion": 1.2,
       "position": [
         900,
-        300
+        500
       ],
       "credentials": {
         "telegramApi": {
@@ -87,6 +87,57 @@
           "name": "SMB Telegram (leads bot)"
         }
       }
+    },
+    {
+      "parameters": {
+        "httpMethod": "POST",
+        "path": "owner-notify",
+        "responseMode": "onReceived",
+        "options": {
+          "allowedOrigins": "*"
+        }
+      },
+      "id": "b0000000-1111-2222-3333-888888888888",
+      "name": "Owner notify webhook",
+      "type": "n8n-nodes-base.webhook",
+      "typeVersion": 2,
+      "position": [
+        240,
+        500
+      ],
+      "webhookId": "smb-owner-notify-webhook-0001"
+    },
+    {
+      "parameters": {
+        "conditions": {
+          "options": {
+            "caseSensitive": true,
+            "leftValue": "",
+            "typeValidation": "strict"
+          },
+          "conditions": [
+            {
+              "id": "b0000000-1111-2222-3333-aaaaaaaaaaaa",
+              "leftValue": "={{ $json.body.notify_channel }}",
+              "rightValue": "telegram",
+              "operator": {
+                "type": "string",
+                "operation": "equals"
+              }
+            }
+          ],
+          "combinator": "and"
+        },
+        "options": {}
+      },
+      "id": "b0000000-1111-2222-3333-999999999999",
+      "name": "Telegram channel?",
+      "type": "n8n-nodes-base.if",
+      "typeVersion": 2,
+      "position": [
+        460,
+        500
+      ]
     }
   ],
   "connections": {
@@ -112,7 +163,18 @@
         ]
       ]
     },
-    "Save to CRM (bookings)": {
+    "Owner notify webhook": {
+      "main": [
+        [
+          {
+            "node": "Telegram channel?",
+            "type": "main",
+            "index": 0
+          }
+        ]
+      ]
+    },
+    "Telegram channel?": {
       "main": [
         [
           {