feat: add ESLint rule for schema key naming convention in cache and preference schemas

- Introduced a new ESLint rule to enforce a specific naming convention for schema keys: `namespace.sub.key_name`.
- Updated cache and preference schema files to include documentation on the naming convention and examples of valid/invalid keys.
- Modified existing keys in cache schemas to comply with the new convention.

eslint.config.mjs

@@ -157,4 +157,60 @@ export default defineConfig([
       // ]
     }
   },
+  // Schema key naming convention (cache & preferences)
+  {
+    files: ['packages/shared/data/cache/cacheSchemas.ts', 'packages/shared/data/preference/preferenceSchemas.ts'],
+    plugins: {
+      'data-schema-key': {
+        rules: {
+          'valid-key': {
+            meta: {
+              type: 'problem',
+              docs: {
+                description: 'Enforce schema key naming convention: namespace.sub.key_name',
+                recommended: true
+              },
+              messages: {
+                invalidKey:
+                  'Schema key "{{key}}" must follow format: namespace.sub.key_name (e.g., app.user.avatar).'
+              }
+            },
+            create(context) {
+              const VALID_KEY_PATTERN = /^[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+$/
+
+              return {
+                TSPropertySignature(node) {
+                  if (node.key.type === 'Literal' && typeof node.key.value === 'string') {
+                    const key = node.key.value
+                    if (!VALID_KEY_PATTERN.test(key)) {
+                      context.report({
+                        node: node.key,
+                        messageId: 'invalidKey',
+                        data: { key }
+                      })
+                    }
+                  }
+                },
+                Property(node) {
+                  if (node.key.type === 'Literal' && typeof node.key.value === 'string') {
+                    const key = node.key.value
+                    if (!VALID_KEY_PATTERN.test(key)) {
+                      context.report({
+                        node: node.key,
+                        messageId: 'invalidKey',
+                        data: { key }
+                      })
+                    }
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    rules: {
+      'data-schema-key/valid-key': 'error'
+    }
+  }
 ])

packages/shared/data/cache/cacheSchemas.ts

@@ -1,5 +1,27 @@
 import type * as CacheValueTypes from './cacheValueTypes'
 
+/**
+ * Cache Schema Definitions
+ *
+ * ## Key Naming Convention
+ *
+ * All cache keys MUST follow the format: `namespace.sub.key_name`
+ *
+ * Rules:
+ * - At least 2 segments separated by dots (.)
+ * - Each segment uses lowercase letters, numbers, and underscores only
+ * - Pattern: /^[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+$/
+ *
+ * Examples:
+ * - 'app.user.avatar' (valid)
+ * - 'chat.multi_select_mode' (valid)
+ * - 'minapp.opened_keep_alive' (valid)
+ * - 'userAvatar' (invalid - missing dot separator)
+ * - 'App.user' (invalid - uppercase not allowed)
+ *
+ * This convention is enforced by ESLint rule: data-schema-key/valid-key
+ */
+
 /**
  * Use cache schema for renderer hook
  */
@@ -63,11 +85,11 @@ export const DefaultUseCache: UseCacheSchema = {
  * Use shared cache schema for renderer hook
  */
 export type UseSharedCacheSchema = {
-  'example-key': string
+  'example_scope.example_key': string
 }
 
 export const DefaultUseSharedCache: UseSharedCacheSchema = {
-  'example-key': 'example default value'
+  'example_scope.example_key': 'example default value'
 }
 
 /**
@@ -75,11 +97,11 @@ export const DefaultUseSharedCache: UseSharedCacheSchema = {
  * This ensures type safety and prevents key conflicts
  */
 export type RendererPersistCacheSchema = {
-  'example-key': string
+  'example_scope.example_key': string
 }
 
 export const DefaultRendererPersistCache: RendererPersistCacheSchema = {
-  'example-key': 'example default value'
+  'example_scope.example_key': 'example default value'
 }
 
 /**

packages/shared/data/preference/preferenceSchemas.ts

@@ -6,6 +6,23 @@
  * To update this file, modify classification.json and run:
  * node .claude/data-classify/scripts/generate-preferences.js
  *
+ * ## Key Naming Convention
+ *
+ * All preference keys MUST follow the format: `namespace.sub.key_name`
+ *
+ * Rules:
+ * - At least 2 segments separated by dots (.)
+ * - Each segment uses lowercase letters, numbers, and underscores only
+ * - Pattern: /^[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+$/
+ *
+ * Examples:
+ * - 'app.user.avatar' (valid)
+ * - 'chat.multi_select_mode' (valid)
+ * - 'userAvatar' (invalid - missing dot separator)
+ * - 'App.user' (invalid - uppercase not allowed)
+ *
+ * This convention is enforced by ESLint rule: data-schema-key/valid-key
+ *
  * === AUTO-GENERATED CONTENT START ===
  */