feat: Chatbot-Workflows mit Ollama-Memory und Session-Management

- docker-compose: extra_hosts für host.docker.internal (Ollama-Zugang)
- ollama-chatbot: Gesprächsverlauf per session_id in PostgreSQL
- ollama-chat-cleanup: stündliche TTL-Bereinigung (2h Inaktivität)
- ollama-chat-delete: DELETE /webhook/chat-session Endpoint

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

imports/workflows/ollama-chat-cleanup.json

@@ -0,0 +1,53 @@
+{
+  "id": "1002",
+  "name": "Chatbot Session Cleanup (TTL 2h)",
+  "nodes": [
+    {
+      "parameters": {
+        "rule": {
+          "interval": [{ "field": "hours", "hoursInterval": 1 }]
+        }
+      },
+      "id": "node-sc-001",
+      "name": "Jede Stunde",
+      "type": "n8n-nodes-base.scheduleTrigger",
+      "typeVersion": 1.2,
+      "position": [100, 300]
+    },
+    {
+      "parameters": {
+        "operation": "executeQuery",
+        "query": "DELETE FROM chat_sessions WHERE updated_at < NOW() - INTERVAL '2 hours' RETURNING session_id",
+        "additionalFields": {}
+      },
+      "id": "node-pg-003",
+      "name": "Delete Expired Sessions",
+      "type": "n8n-nodes-base.postgres",
+      "typeVersion": 2.5,
+      "position": [300, 300],
+      "credentials": {
+        "postgres": {
+          "id": "SETUP_REQUIRED",
+          "name": "n8n PostgreSQL"
+        }
+      }
+    },
+    {
+      "parameters": {
+        "jsCode": "const deleted = $input.all().map(i => i.json.session_id).filter(Boolean);\nconsole.log(`[Cleanup] ${deleted.length} Session(s) gelöscht:`, deleted);\nreturn [{ json: { deleted_count: deleted.length, deleted_sessions: deleted } }];"
+      },
+      "id": "node-cd-004",
+      "name": "Log Result",
+      "type": "n8n-nodes-base.code",
+      "typeVersion": 2,
+      "position": [500, 300]
+    }
+  ],
+  "connections": {
+    "Jede Stunde":             { "main": [[{ "node": "Delete Expired Sessions", "type": "main", "index": 0 }]] },
+    "Delete Expired Sessions": { "main": [[{ "node": "Log Result",              "type": "main", "index": 0 }]] }
+  },
+  "active": false,
+  "settings": { "executionOrder": "v1" },
+  "tags": []
+}