refactor: migrate from qdrant to postgres+pgvector

manifests/postgres.yaml

@@ -0,0 +1,66 @@
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: postgres
+  namespace: knowledge-mcp
+  labels:
+    app: postgres
+spec:
+  serviceName: postgres
+  replicas: 1
+  selector:
+    matchLabels:
+      app: postgres
+  template:
+    metadata:
+      labels:
+        app: postgres
+    spec:
+      containers:
+        - name: postgres
+          image: ankane/pgvector:v0.5.1
+          ports:
+            - containerPort: 5432
+              name: postgres
+          env:
+            - name: POSTGRES_USER
+              value: "postgres"
+            - name: POSTGRES_PASSWORD
+              value: "password"
+            - name: POSTGRES_DB
+              value: "knowledge"
+            - name: PGDATA
+              value: "/var/lib/postgresql/data/pgdata"
+          volumeMounts:
+            - name: storage
+              mountPath: /var/lib/postgresql/data
+          resources:
+            requests:
+              cpu: "100m"
+              memory: "256Mi"
+            limits:
+              cpu: "500m"
+              memory: "512Mi"
+  volumeClaimTemplates:
+    - metadata:
+        name: storage
+      spec:
+        accessModes: [ "ReadWriteOnce" ]
+        resources:
+          requests:
+            storage: 5Gi
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: postgres
+  namespace: knowledge-mcp
+  labels:
+    app: postgres
+spec:
+  ports:
+    - port: 5432
+      targetPort: 5432
+      name: postgres
+  selector:
+    app: postgres