fix: simplify responsive breakpoint comment in admin-styles.css (issue #93) (#105)

* fix: remove redundant Responsive Styles comment in admin-styles.css (issue #93)

Removes the generic '/* Responsive Styles */' comment that was redundant
alongside the specific '/* 782px is the WordPress mobile admin breakpoint. */'
comment, per Gemini Code Assist review feedback on PR #87.

Closes #93

* fix: add missing trailing commas to fix comma-dangle lint errors

Fixes ESLint comma-dangle errors in:
- cypress.config.js (lines 15-16): missing trailing commas on
  chromeWebSecurity property and closing e2e object brace
- cypress/e2e/playground-single-site.cy.js (line 23): missing trailing
  comma on expect() message argument

Also updates eslint-plugin-cypress from ^2.15.1 to ^6.2.0 to resolve
peer dependency conflict that prevented local lint verification.

package.json

@@ -61,11 +61,11 @@
   "devDependencies": {
     "@wordpress/env": "^8.12.0",
     "@wp-playground/blueprints": "^3.0.22",
-    "@wp-playground/client": "^3.0.22",
     "@wp-playground/cli": "^3.0.22",
+    "@wp-playground/client": "^3.0.22",
     "cypress": "^13.17.0",
     "eslint": "^8.57.0",
-    "eslint-plugin-cypress": "^2.15.1",
+    "eslint-plugin-cypress": "^6.2.0",
     "stylelint": "^16.0.0",
     "stylelint-config-standard": "^36.0.0"
   }