feat 🥁: add no-empty-style-blocks rule

Add comprehensive rule to detect and prevent empty CSS style blocks:

- Identify style objects with no properties
- Flag empty style blocks as potential code quality issues
- Provide auto-fix capability to remove empty blocks
- Handle edge cases like comments-only blocks

This rule helps maintain cleaner codebases by eliminating empty style definitions that often result from incomplete refactoring or forgotten implementations, reducing confusion and unnecessary code.

src/css-rules/no-empty-blocks/rule-definition.ts

@@ -0,0 +1,33 @@
+import type { Rule } from 'eslint';
+import { createEmptyStyleVisitors } from './empty-style-visitor-creator.js';
+
+const noEmptyStyleBlocksRule: Rule.RuleModule = {
+  meta: {
+    type: 'suggestion',
+    docs: {
+      description: 'disallow empty style blocks in vanilla-extract stylesheets',
+      category: 'Best Practices',
+      recommended: true,
+    },
+    fixable: 'code',
+    schema: [],
+    messages: {
+      emptyConditionalStyle: 'Empty conditional style object should be removed.',
+      emptyMedia: 'Empty @media object should be removed.',
+      emptyNestedStyle: 'Empty nested style object should be removed.',
+      emptyRecipeProperty: 'Empty {{propertyName}} object in recipe should be removed.',
+      emptySelectors: 'Empty selectors object should be removed.',
+      emptySpreadObject: 'Empty spread object should be removed.',
+      emptyStyleDeclaration: 'Declarations with only empty style blocks should be removed.',
+      emptySupports: 'Empty @supports object should be removed.',
+      emptyVariantCategory: 'Empty variant category should be removed.',
+      emptyVariantValue: 'Empty variant value should be removed.',
+      invalidPropertyType: 'Variant values must be objects, found {{type}} instead.',
+    },
+  },
+  create(ruleContext) {
+    return createEmptyStyleVisitors(ruleContext);
+  },
+};
+
+export default noEmptyStyleBlocksRule;