fix(hover-card): maiden name false positive, placeholder on non-empty editor, card persistence

- PersonHoverCard: alias is compared against both `lastName` and `displayName`
  before showing as maiden name — prevents false positive when alias is stored
  as the full current name (e.g. "Maria Schmidt" ≠ "Schmidt" but name unchanged)
- PersonMentionEditor: data-placeholder was set statically so the CSS ::before
  rule showed the placeholder on any blur even with content; now a $effect
  toggles the attribute based on editor.isEmpty
- TranscriptionReadView: hovering onto the card itself cancels the 150ms close
  timer so the card stays open while reading it; leaving the card closes it
  immediately — onmouseenter/onmouseleave wired through PersonHoverCard props
- hoverCardPosition: removed scrollX/scrollY offset since the card is now
  position:fixed (scroll is already baked into getBoundingClientRect coords)
- MentionDropdown: raised z-index from z-20 to z-50 to render above the hover card
- vite.config.ts: pre-bundle Tiptap packages to avoid HMR waterfall on first load

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

frontend/src/lib/components/PersonMentionEditor.svelte

@@ -224,7 +224,6 @@ onMount(() => {
 				role: 'textbox',
 				'aria-multiline': 'true',
 				'aria-label': m.transcription_editor_aria_label(),
-				...(placeholder ? { 'data-placeholder': placeholder } : {}),
 				class: [
 					'min-h-[120px] px-1 py-2.5',
 					'font-serif text-base leading-relaxed text-ink',
@@ -255,6 +254,20 @@ onDestroy(() => {
 	editor?.destroy();
 });
 
+// Keep the data-placeholder attribute in sync with actual emptiness so the
+// placeholder CSS only fires when there is no content (not just on blur).
+$effect(() => {
+	if (!editor || !placeholder) return;
+	void value; // track value as dependency so this re-runs on content changes
+	const inner = editorEl?.querySelector('.tiptap-editor-inner') as HTMLElement | null;
+	if (!inner) return;
+	if (editor.isEmpty) {
+		inner.setAttribute('data-placeholder', placeholder);
+	} else {
+		inner.removeAttribute('data-placeholder');
+	}
+});
+
 // Keep editor in sync with the reactive `disabled` prop. Tiptap's setEditable
 // flips contenteditable on the inner DOM and stops accepting input — matches
 // the textarea's old `disabled` semantics for keyboard users (WCAG 2.1.1).