Add spanner plugin (#2316)

.claude-plugin/marketplace.json

@@ -2448,6 +2448,20 @@
       },
       "homepage": "https://sourcegraph.com"
     },
+    {
+      "name": "spanner",
+      "description": "Connect and interact with Spanner data using natural language.",
+      "author": {
+        "name": "Google LLC"
+      },
+      "category": "database",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/gemini-cli-extensions/spanner.git",
+        "sha": "d4678e2bc04f60f3dfcdb6b916df28e63a0d615f"
+      },
+      "homepage": "https://github.com/gemini-cli-extensions/spanner"
+    },
     {
       "name": "spotify-ads-api",
       "description": "Manage Spotify ad campaigns with natural language. Create campaigns, ad sets, ads, pull reports, and handle OAuth — all through conversation.",