Update all distributions to use separate kvstore/sqlstore backends

- Ensures context-aware parsing works correctly
- Metadata uses kvstore backend, inference uses sqlstore backend
- Both can share same postgres/sqlite config but parsed as correct type

llama_stack/distributions/postgres-demo/run.yaml

@@ -73,7 +73,14 @@ providers:
     provider_type: remote::model-context-protocol
 persistence:
   backends:
-    default:
+    kvstore:
+      type: postgres
+      host: ${env.POSTGRES_HOST:=localhost}
+      port: ${env.POSTGRES_PORT:=5432}
+      db: ${env.POSTGRES_DB:=llamastack}
+      user: ${env.POSTGRES_USER:=llamastack}
+      password: ${env.POSTGRES_PASSWORD:=llamastack}
+    sqlstore:
       type: postgres
       host: ${env.POSTGRES_HOST:=localhost}
       port: ${env.POSTGRES_PORT:=5432}
@@ -82,9 +89,9 @@ persistence:
       password: ${env.POSTGRES_PASSWORD:=llamastack}
   stores:
     metadata:
-      backend: default
+      backend: kvstore
     inference:
-      backend: default
+      backend: sqlstore
 models:
 - metadata: {}
   model_id: ${env.INFERENCE_MODEL}

llama_stack/distributions/watsonx/run.yaml

@@ -105,14 +105,17 @@ providers:
         db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/files_metadata.db
 persistence:
   backends:
-    default:
+    kvstore:
       type: sqlite
-      db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/registry.db
+      db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/kvstore.db
+    sqlstore:
+      type: sqlite
+      db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/watsonx}/sqlstore.db
   stores:
     metadata:
-      backend: default
+      backend: kvstore
     inference:
-      backend: default
+      backend: sqlstore
 models:
 - metadata: {}
   model_id: meta-llama/llama-3-3-70b-instruct