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/TranscriptionEditView.svelte

@@ -10,12 +10,21 @@ type Props = {
 	documentId: string;
 	blocks: TranscriptionBlockData[];
 	canComment: boolean;
+	currentUserId: string | null;
 	onBlockFocus: (blockId: string) => void;
 	onSaveBlock: (blockId: string, text: string) => Promise<void>;
 	onDeleteBlock: (blockId: string) => Promise<void>;
 };
 
-let { documentId, blocks, canComment, onBlockFocus, onSaveBlock, onDeleteBlock }: Props = $props();
+let {
+	documentId,
+	blocks,
+	canComment,
+	currentUserId,
+	onBlockFocus,
+	onSaveBlock,
+	onDeleteBlock
+}: Props = $props();
 
 let activeBlockId: string | null = $state(null);
 let saveStates = new SvelteMap<string, SaveState>();
@@ -156,6 +165,7 @@ $effect(() => {
 						active={activeBlockId === block.id}
 						saveState={getSaveState(block.id)}
 						canComment={canComment}
+						currentUserId={currentUserId}
 						onTextChange={(text) => handleTextChange(block.id, text)}
 						onFocus={() => handleFocus(block.id)}
 						onDeleteClick={() => handleDelete(block.id)}