chore: restore .gemini conductor agent files

.gemini/tools/get_git_diff.json

@@ -0,0 +1,25 @@
+{
+  "name": "get_git_diff",
+  "description": "Returns the git diff for a file or directory. Use this to review changes efficiently without reading entire files.",
+  "parameters": {
+    "type": "object",
+    "properties": {
+      "path": {
+        "type": "string",
+        "description": "Path to the file or directory."
+      },
+      "base_rev": {
+        "type": "string",
+        "description": "Base revision (e.g. 'HEAD', 'HEAD~1', or a commit hash). Defaults to 'HEAD'."
+      },
+      "head_rev": {
+        "type": "string",
+        "description": "Head revision (optional)."
+      }
+    },
+    "required": [
+      "path"
+    ]
+  },
+  "command": "python scripts/tool_call.py get_git_diff"
+}