fix: improve cross-tool AI config accuracy and consistency

- Fix import extensions: .js → .ts/.tsx (tsup converts for ESM)
- Fix renderHookSSR import path to match actual codebase
- Add mobile test filename distinction (.spec.ts vs .test.ts)
- Add missing rules: strict boolean checks, cleanup, zero deps,
  performance patterns, CLI commands

Author: kimyouknow

.cursorrules

@@ -15,8 +15,10 @@ Mobile depends on core. Core must NOT depend on mobile.
 - Named functions in useEffect: `useEffect(function handleResize() { ... }, [])`
 - Named exports only, no default exports
 - No `any` — strict TypeScript
-- `.js` extensions in relative imports
+- `.ts`/`.tsx` extensions in source imports (tsup converts to `.js`)
+- Strict boolean checks: `value !== undefined` not `if (value)`
 - Zero runtime dependencies
+- Always return cleanup in useEffect to remove listeners
 
 ## SSR-Safe Pattern
 
@@ -44,13 +46,27 @@ useEffect(function syncBrowserState() {
 
 Each hook in own folder: `src/hooks/useHookName/`
 
-- `index.ts`, `useHookName.ts`, `useHookName.spec.ts`, `useHookName.ssr.test.ts`
+- `index.ts`, `useHookName.ts`, `useHookName.spec.ts` (core) / `.test.ts` (mobile), `useHookName.ssr.test.ts`
 - Docs: `useHookName.md` + `ko/useHookName.md`
 
 ## JSDoc
 
 Required tags: `@description`, `@param`, `@returns`, `@example`
 
+## Performance
+
+- Throttle subscriptions at ~16ms (60fps)
+- Use `startTransition` for non-urgent state updates
+
+## Commands
+
+```bash
+yarn build      # Build all (tsup)
+yarn test       # Run tests (Vitest)
+yarn fix        # Auto-fix lint + format
+yarn typecheck  # Type check (tsc --noEmit)
+```
+
 ## Commits
 
 Format: `<type>(<scope>): <description>`

.github/copilot-instructions.md

@@ -12,7 +12,10 @@
 - Named functions in useEffect: `useEffect(function handleResize() { ... }, [])`
 - No default exports — named exports only
 - No `any` types — strict TypeScript
-- Include `.js` in relative imports for ESM
+- Use `.ts`/`.tsx` extensions in source imports (tsup converts to `.js`)
+- Strict boolean checks: `value !== undefined` not `if (value)`
+- Zero runtime dependencies
+- Always return cleanup in useEffect to remove listeners
 
 ## SSR-Safe Pattern (CRITICAL)
 
@@ -39,7 +42,7 @@ Never call browser APIs during state initialization.
 - 100% coverage required (Vitest)
 - SSR test required for browser API hooks:
   ```ts
-  import { renderHookSSR } from '../utils/renderHookSSR';
+  import { renderHookSSR } from '../../_internal/test-utils/renderHookSSR.tsx';
   it('is safe on server side rendering', () => {
     const result = renderHookSSR.serverOnly(() => useHookName());
     expect(result.current).toBeDefined();
@@ -68,8 +71,17 @@ Every public API requires:
 src/hooks/useHookName/
 ├── index.ts               # Re-export
 ├── useHookName.ts         # Implementation
-├── useHookName.spec.ts    # Tests
+├── useHookName.spec.ts    # Tests (core) / useHookName.test.ts (mobile)
 ├── useHookName.ssr.test.ts # SSR tests
 ├── useHookName.md         # English docs
 └── ko/useHookName.md      # Korean docs
 ```
+
+## Commands
+
+```bash
+yarn build      # Build all packages (tsup)
+yarn test       # Run tests (Vitest)
+yarn fix        # Auto-fix lint + format
+yarn typecheck  # Type check (tsc --noEmit)
+```

AGENTS.md

@@ -43,7 +43,7 @@ src/hooks/useHookName/
 - **`type` over `interface`** — Always use `type` for type aliases
 - **Named functions in useEffect** — `useEffect(function handleResize() { ... }, [])` not arrow functions
 - **Strict boolean checks** — `value !== undefined` not `if (value)`
-- **Import extensions** — Include `.js` in relative imports for ESM compliance
+- **Import extensions** — Use `.ts`/`.tsx` extensions in source imports (tsup converts to `.js` for ESM output)
 - **Named exports only** — No default exports
 - **No `any` types** — Full TypeScript strict mode
 - **Zero runtime dependencies**
@@ -72,15 +72,22 @@ Never initialize state with browser API calls (causes hydration mismatch).
 
 - **100% coverage mandatory** — Enforced by Vitest coverage threshold
 - **SSR tests required** — All hooks accessing browser APIs need `.ssr.test.ts`
+- **useEffect cleanup** — Always return cleanup in useEffect to remove listeners
 - **SSR test pattern**:
   ```ts
-  import { renderHookSSR } from '../utils/renderHookSSR';
+  import { renderHookSSR } from '../../_internal/test-utils/renderHookSSR.tsx';
   it('is safe on server side rendering', () => {
     const result = renderHookSSR.serverOnly(() => useHookName());
     expect(result.current).toBeDefined();
   });
   ```
 
+### Performance Patterns
+
+- Throttle subscriptions at ~16ms (60fps)
+- Deduplicate to skip unchanged updates
+- Use `startTransition` for non-urgent state updates (React 18+)
+
 ## Documentation
 
 - **Bilingual**: English + Korean (co-located in hook folders)