fix: resolve react-is version mismatch and .gitattributes syntax error (#2650)

Override react-is to v19.2.4 via pnpm overrides to fix CounterLabel
crash. react-is@18.3.1 checks for Symbol(react.element) but React 19
uses Symbol(react.transitional.element), causing isElement() to return
false in @primer/react's ButtonBase and blow up at runtime.

Also fix .gitattributes syntax error from stray merge conflict marker.

Author: codebytere

.gitattributes

@@ -5,4 +5,4 @@
 *.snap linguist-generated=true
 
 # GraphQL Codegen outputs
-+ src/renderer/utils/api/graphql/generated/**/*.ts linguist-generated=true
+src/renderer/utils/api/graphql/generated/**/*.ts linguist-generated=true

package.json

@@ -137,7 +137,10 @@
       "electron",
       "esbuild",
       "unrs-resolver"
-    ]
+    ],
+    "overrides": {
+      "react-is": "19.2.4"
+    }
   },
   "lint-staged": {
     "*": "biome check --no-errors-on-unmatched",