fix: mobile diff comment input placeholder and review comments pill

Use a shorter comment placeholder on mobile (drop the Cmd+Enter hint that has
no touch equivalent) so it no longer clips in the auto-sized textarea.

Add a remove (x) button to the review comments pill, matching the annotation
and dev-server-log pills, and stop the mobile touch-target min-height/width
from inflating the pill close buttons.

packages/ui/src/lib/i18n/messages/ko.ts

@@ -1243,6 +1243,7 @@ export const dict: Record<I18nKey, string> = {
   'rightSidebar.contextNotesTodo.toast.readPlanFileFailed': '플랜 파일 읽기 실패',
   'inlineComment.range.lines': '줄 {start}-{end}',
   'inlineComment.input.placeholder': '댓글 추가… (Cmd+Enter로 저장)',
+  'inlineComment.input.placeholderShort': '댓글 추가…',
   'inlineComment.actions.cancel': '취소',
   'inlineComment.actions.save': '저장',
   'inlineComment.actions.comment': '댓글',
@@ -1776,6 +1777,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.chatInput.toast.openSessionFirst': '먼저 세션을 여세요',
   'chat.chatInput.toast.togglePermissionAutoAcceptFailed': '권한 자동 승인 전환에 실패했습니다',
   'chat.chatInput.reviewComments': '검토 댓글:',
+  'chat.chatInput.reviewCommentsRemove': '검토 댓글 제거',
   'chat.chatInput.devServerLogs': 'Dev Server 로그:',
   'chat.chatInput.devServerLogsRemove': 'Dev Server 로그 제거',
   'chat.chatInput.previewAnnotations': '미리보기 주석:',