Fix cursor positioning, resize, and paste; add App tests and Cursor rules

- Use CoreGraphics (core-graphics crate) for global mouse position instead
  of Tauri's window-relative cursor_position() which fails when hidden
- Switch to titleBarStyle overlay with hiddenTitle for native resize handles
  while keeping the frameless look (decorations:false had no resize affordance)
- Fix paste_and_refocus: use .output() instead of .spawn() so osascript
  actually completes, increase delay to 250ms for reliable app refocus
- Add comprehensive App.test.tsx (7 integration tests) bringing total to 47
- Add multi-select and type badge tests for ClipboardList and ContextMenu
- Update Tauri mock in setup.ts with innerSize/scaleFactor for resize tests
- Create .cursor/rules/ with 4 rule files for project conventions
- Add npm run lint and npm run check scripts
- Update README with full usage table and current test counts (74 total)

Co-authored-by: Cursor <cursoragent@cursor.com>

.cursor/rules/project-overview.mdc

@@ -0,0 +1,31 @@
+---
+description: maCopy project overview and architecture
+alwaysApply: true
+---
+
+# maCopy — macOS Clipboard Manager
+
+Tauri 2 desktop app: Rust backend + React/TypeScript frontend.
+
+## Architecture
+
+- `src-tauri/src/lib.rs` — App setup, tray icon, global hotkey (Cmd+Shift+V), window management
+- `src-tauri/src/clipboard.rs` — Background polling thread (500ms), SHA-256 dedup, arboard crate
+- `src-tauri/src/db.rs` — SQLite via rusqlite, FTS5 full-text search, settings CRUD
+- `src-tauri/src/commands.rs` — Tauri IPC commands exposed to frontend
+- `src/App.tsx` — Main React component, state, keyboard nav, multi-select
+- `src/components/` — SearchBar, ClipboardList, ContextMenu, SettingsPanel
+
+## Key Patterns
+
+- Window positions near cursor via CoreGraphics (`core-graphics` crate)
+- Paste-to-previous-app: hide window → 250ms delay → AppleScript `Cmd+V`
+- Window uses `titleBarStyle: "overlay"` with `hiddenTitle` for native resize + frameless look
+- Settings stored in SQLite `settings` table as key-value pairs
+- Clipboard entries deduplicated by SHA-256 hash, auto-trimmed to max_history
+
+## Testing
+
+- Rust: `cargo test` in `src-tauri/` — 27 unit tests (db, clipboard hashing)
+- Frontend: `npx vitest run` — 47 tests (App, SearchBar, ClipboardList, ContextMenu, SettingsPanel)
+- Tauri APIs mocked in `src/test/setup.ts`

.cursor/rules/react-frontend.mdc

@@ -0,0 +1,33 @@
+---
+description: React/TypeScript frontend patterns for Tauri app
+globs: src/**/*.{ts,tsx}
+alwaysApply: false
+---
+
+# Frontend Conventions
+
+## Component Structure
+
+- Functional components with hooks, no class components
+- Types in `src/types.ts`, shared between components
+- Test files colocated: `Component.test.tsx` next to `Component.tsx`
+- Test factories in `src/test/factories.ts` (`makeEntry`, `makeSettings`)
+
+## Tauri IPC
+
+- Use `invoke()` from `@tauri-apps/api/core` to call Rust commands
+- Use `writeText()` from `@tauri-apps/plugin-clipboard-manager` for clipboard writes
+- Mock all Tauri APIs in `src/test/setup.ts` for Vitest
+
+## State Management
+
+- App-level state in `App.tsx` via `useState`/`useCallback`
+- Multi-select: `selectedIds` (Set), `anchorIndex`, `focusIndex`
+- Selection actions: `selectOnly` (plain click), `toggleSelect` (Cmd+Click), `selectRange` (Shift+Click/Arrow)
+
+## Styling
+
+- Tailwind CSS v4 with custom theme tokens in `src/index.css`
+- Theme colors: `--color-surface`, `--color-accent`, `--color-text-primary`, etc.
+- Dark mode via `@media (prefers-color-scheme: dark)` overrides in CSS
+- Never use inline styles except for dynamic positioning (ContextMenu)

.cursor/rules/rust-backend.mdc

@@ -0,0 +1,28 @@
+---
+description: Rust backend conventions for Tauri commands and database
+globs: src-tauri/src/**/*.rs
+alwaysApply: false
+---
+
+# Rust Backend Conventions
+
+## Tauri Commands
+
+- All IPC commands live in `commands.rs`, annotated with `#[tauri::command]`
+- Commands that need DB access take `State<'_, DbState>`
+- Commands that need the app handle take `app: tauri::AppHandle`
+- Return `Result<T, String>` — map errors with `.map_err(|e| e.to_string())`
+- Register every new command in `lib.rs` → `invoke_handler`
+
+## Database (db.rs)
+
+- `Database` wraps `Mutex<Connection>` for thread safety
+- Use `Database::in_memory()` in tests, `Database::new()` in production
+- Settings are key-value in the `settings` table; add defaults in `init_tables()`
+- FTS5 table `clipboard_fts` syncs via triggers on insert/delete
+
+## macOS-Specific Code
+
+- Gate with `#[cfg(target_os = "macos")]`
+- Cursor position: use `core-graphics` crate's `CGEvent` (not Tauri's `cursor_position()` which is window-relative)
+- AppleScript for paste simulation: always use `.output()` not `.spawn()` to ensure execution completes

.cursor/rules/testing.mdc

@@ -0,0 +1,29 @@
+---
+description: Testing conventions for Rust and TypeScript
+globs: "**/*.test.{ts,tsx}"
+alwaysApply: false
+---
+
+# Testing Conventions
+
+## Rust Tests (cargo test)
+
+- In-module `#[cfg(test)]` blocks using `Database::in_memory()`
+- Test naming: `snake_case` describing behavior (e.g. `trim_preserves_pinned_entries`)
+- All tests must pass before committing: `cd src-tauri && cargo test`
+
+## Frontend Tests (Vitest)
+
+- Use `@testing-library/react` with `jsdom` environment
+- Mock Tauri APIs in `src/test/setup.ts` — never call real IPC in tests
+- Use `makeEntry()` and `makeSettings()` factories for test data
+- Call `resetIdCounter()` in `beforeEach` when IDs matter
+- When testing async Tauri commands, use `waitFor()` assertions
+- Guard `scrollIntoView` with optional chaining (`el?.scrollIntoView?.()`) since jsdom doesn't implement it
+
+## Running Tests
+
+```bash
+cd src-tauri && cargo test    # Rust: 27 tests
+npx vitest run                # Frontend: 47 tests
+```