Cupertino gallery app (#2715)

Resolves #2519 

Part of the larger effort to bring the samples/repo into a stable and
maintainable condition that _also_ remains useful. See: #2409

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I have added sample code updates to the [changelog].
- [x] I updated/added relevant documentation (doc comments with `///`).

.gemini/settings.json

@@ -1,4 +1,7 @@
 {
+  "context": {
+    "fileName": "/.prompts/llm.md"
+  },
   "mcpServers": {
     "dart": {
       "command": "dart",
@@ -6,6 +9,5 @@
         "mcp-server"
       ]
     }
-  },
-  "contextFileName": "/.prompts/llm.md"
-}
+  }
+}

.gemini/settings.json.orig

@@ -0,0 +1,11 @@
+{
+  "mcpServers": {
+    "dart": {
+      "command": "dart",
+      "args": [
+        "mcp-server"
+      ]
+    }
+  },
+  "contextFileName": "/.prompts/llm.md"
+}