fix: sync attachment changes to store and skip spurious auto-save

Two issues fixed:

1. Attachment operations (upload, feature, remove) only updated the local
   editor state, not the notes store. Before auto-save, this was masked
   because saveAndClose always called updateNote, whose PATCH response
   refreshed the store. With auto-save skipping redundant saves, the store
   was never updated with attachment changes. Now attachment handlers
   update the store directly.

2. TiptapEditor fires onUpdate on init with round-tripped markdown that
   can differ from the original. Added an autoSaveReady guard to absorb
   this initial normalization as the baseline, preventing spurious saves
   when reopening existing notes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/components/NoteEditor.svelte

@@ -71,6 +71,9 @@
 	let isSaving = false;
 	let savingPromise: Promise<void> | null = null;
 	let autoSaveTimer: ReturnType<typeof setTimeout> | undefined;
+	// TiptapEditor fires onUpdate on init with round-tripped markdown that may differ
+	// from the original. Track whether auto-save should be active yet.
+	let autoSaveReady = isNew;
 
 	function hasUnsavedChanges(): boolean {
 		return (
@@ -126,6 +129,13 @@
 		const _col = color;
 		const _cm = checklistMode;
 
+		if (!autoSaveReady) {
+			// Absorb TiptapEditor's initial content normalization as the baseline
+			lastSavedContent = _c;
+			autoSaveReady = true;
+			return;
+		}
+
 		if (_t === lastSavedTitle && _c === lastSavedContent && _col === lastSavedColor && _cm === lastSavedChecklistMode) return;
 		if (!_t.trim() && !_c.trim()) return;
 
@@ -272,7 +282,13 @@
 	});
 
 	function handleAttachmentUpload(attachment: Attachment) {
-		attachmentsList = [...attachmentsList, attachment];
+		const updated = [...attachmentsList, attachment];
+		attachmentsList = updated;
+		if (noteId) {
+			notes.update((list) =>
+				list.map((n) => (n.id === noteId ? { ...n, attachments: updated } : n))
+			);
+		}
 	}
 
 	async function handleToggleFeatured(attachmentId: string, featured: boolean) {
@@ -284,9 +300,14 @@
 				body: JSON.stringify({ featured })
 			});
 			if (res.ok) {
-				attachmentsList = attachmentsList.map((a) =>
+				const updated = attachmentsList.map((a) =>
 					a.id === attachmentId ? { ...a, featured } : a
 				);
+				attachmentsList = updated;
+				// Keep the notes store in sync so the card reflects featured state
+				notes.update((list) =>
+					list.map((n) => (n.id === noteId ? { ...n, attachments: updated } : n))
+				);
 			}
 		} catch (err) {
 			console.error('Failed to toggle featured:', err);
@@ -299,7 +320,11 @@
 			await fetch(`/api/notes/${noteId}/attachments?attachmentId=${attachmentId}`, {
 				method: 'DELETE'
 			});
-			attachmentsList = attachmentsList.filter((a) => a.id !== attachmentId);
+			const updated = attachmentsList.filter((a) => a.id !== attachmentId);
+			attachmentsList = updated;
+			notes.update((list) =>
+				list.map((n) => (n.id === noteId ? { ...n, attachments: updated } : n))
+			);
 		} catch (err) {
 			console.error('Failed to remove attachment:', err);
 		}