chore(lint): migrate CSS linting to Biome v2.3 (Tailwind v4) and remove stylelint

upgrade @biomejs/biome to ^2.3.2 and migrate biome.json to v2 schema
enable css.parser.tailwindDirectives; ignore .min.css and vendor CSS
remove stylelint deps and .stylelintrc.yaml; switch lint scripts to Biome
update workspace to use Biome for CSS; drop stylelint settings

.github/workflows/ci-build-starters-matrix.yml

@@ -15,7 +15,6 @@ on:
             - "package.json"
             - "pnpm-lock.yaml"
             - "biome.json"
-            - ".stylelintrc.yaml"
             - "vite.config.js"
     pull_request:
         types:
@@ -31,7 +30,6 @@ on:
             - "package.json"
             - "pnpm-lock.yaml"
             - "biome.json"
-            - ".stylelintrc.yaml"
             - "vite.config.js"
 
 permissions:

.github/workflows/ci-lint.yml

@@ -11,7 +11,6 @@ on:
       - "package.json"
       - "pnpm-lock.yaml"
       - "biome.json"
-      - ".stylelintrc.yaml"
       - "vite.config.js"
   pull_request:
     branches: [main]
@@ -22,7 +21,6 @@ on:
       - "package.json"
       - "pnpm-lock.yaml"
       - "biome.json"
-      - ".stylelintrc.yaml"
       - "vite.config.js"
 
 permissions: