chore(v028): final review minor 3건 cleanup

- inklingMedia.ts:39 no-op replace 제거 + 명료한 host+pathname 결합 코멘트
- inbox:open-media 빈 relPath 명시적 거절 (typeof + length 검사)
- NoteCard <img> alt="" decorative 의도 코멘트

472/472 + typecheck 0 유지.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/renderer/inbox/components/NoteCard.tsx

@@ -334,6 +334,7 @@ export function NoteCard({ note, onDeleted, onUpdated, mode = 'inbox', onRestore
       {local.media.length > 0 && (
         <div style={{ marginTop: 10, display: 'flex', flexWrap: 'wrap', gap: 6 }}>
           {local.media.map((m) => (
+            // alt="" — decorative (relPath 는 사용자 의미 X). title 이 hover tooltip.
             <img
               key={m.id}
               src={`inkling-media://${m.relPath}`}