글로벌 키보드 훅 타이핑 버벅임 완화

다른 앱 타이핑 시에도 AX Copilot가 과하게 개입하던 글로벌 키보드 훅의 핫패스를 줄였다.

InputListener는 모든 키마다 파일 대화상자 억제 창 검사를 하지 않고 실제 핫키·캡처·키필터 후보 키에서만 검사하도록 최적화했다.

SnippetExpander는 추적 중이 아닐 때 ';' 시작 키 외에는 즉시 반환하게 바꿔 일반 타이핑 중 반복적인 modifier 상태 확인과 버퍼 처리를 제거했다.

README와 DEVELOPMENT 문서를 2026-04-06 18:34 (KST) 기준으로 갱신했고, Release 빌드 검증에서 경고 0 / 오류 0을 확인했다.

docs/DEVELOPMENT.md

@@ -5002,3 +5002,5 @@ ow + toggle ?쒓컖 ?몄뼱濡??ㅼ떆 ?뺣젹?덈떎.
 - Document update: 2026-04-06 18:24 (KST) - Reworked launcher indexing in `IndexService.cs` from a “full rebuild on every change” structure to a persisted cache plus incremental watcher model. Launcher file-system entries are now saved to `%APPDATA%\AxCopilot\index\launcher-index.json`, loaded immediately at startup, and merged with aliases/built-in app entries before the first search.
 - Document update: 2026-04-06 18:24 (KST) - `FileSystemWatcher` changes are now handled incrementally where possible. File create/delete/rename events update only the affected launcher index entries and debounce cache persistence, while high-impact directory rename/delete cases still fall back to a full rebuild for correctness.
 - Document update: 2026-04-06 18:24 (KST) - `App.xaml.cs` now restores eager cache availability by calling `LoadCachedIndex()` and `StartWatchers()` at startup, while keeping the heavier full scan on the existing `EnsureIndexWarmupStarted()` path. This keeps the launcher responsive from the first open without reintroducing continuous full rescans as idle background work.
+- Document update: 2026-04-06 18:34 (KST) - Reduced the per-keystroke hot-path cost of the global keyboard hook. `InputListener.cs` now performs the suppressed-foreground-window check only when the current key could actually trigger the launcher hotkey, the capture hotkey, or a registered key filter, instead of doing the window-class lookup on every keydown.
+- Document update: 2026-04-06 18:34 (KST) - `SnippetExpander.cs` now short-circuits immediately for normal typing unless snippet tracking is already active or the current key is the `;` trigger. This removes repeated `GetAsyncKeyState` and buffer logic from ordinary typing in other apps and makes the low-level hook substantially lighter under continuous input.