feat(comments): inline edit on click + trash icon for own comments

Own comments:
- Click the text to open inline edit (textarea replaces text)
- Enter saves, Escape cancels
- Small trash icon always visible in bottom-right corner
- Hover on text shows cursor-text + subtle bg highlight

Other people's comments: read-only, no edit/delete affordances.

Re-add currentUserId prop chain for ownership check.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/components/TranscriptionBlock.svelte

@@ -13,6 +13,7 @@ type Props = {
 	active: boolean;
 	saveState: SaveState;
 	canComment: boolean;
+	currentUserId: string | null;
 	onTextChange: (text: string) => void;
 	onFocus: () => void;
 	onDeleteClick: () => void;
@@ -28,6 +29,7 @@ let {
 	active,
 	saveState,
 	canComment,
+	currentUserId,
 	onTextChange,
 	onFocus,
 	onDeleteClick,
@@ -214,6 +216,7 @@ function handleTextareaMouseUp() {
 				blockId={blockId}
 				loadOnMount={true}
 				canComment={canComment}
+				currentUserId={currentUserId}
 				quotedText={selectedQuote}
 				showCompose={commentOpen}
 				onCountChange={(count) => (commentCount = count)}