DRY pass #2, batch 8: stale comments (#5372)

useNoteList no longer names a Search view; the desktop adapter's M10.7 plan
gave way to sync under the local core; local.ts's sharing comment sat above
settings; AccountList and password_resets still said there was no mail path;
NoteEditor kept an orphan checklist-flag comment, a textarea comment from
before blocks, and the link-preview comment above the file picker; the
serialize docstring's growth plan is now what it holds.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/components/NoteEditor.vue

@@ -47,9 +47,6 @@ function setBody(text: string): void {
   blocks.value = splitBlocks(text);
 }
 const labelList = ref<NoteLabel[]>(props.note ? [...props.note.labels] : []);
-// Whether this editor is showing the checklist. A note HAS a checklist (M13 step 2)
-// rather than BEING one, so this is a view flag, not a property of the note: it turns
-// on when the note already carries items, and when someone asks for one.
 const saving = ref(false);
 const root = ref<HTMLElement | null>(null);
 // One element per block, keyed by the block's id — the only thing about a block that
@@ -489,12 +486,6 @@ async function uploadFile(file: File) {
   }
 }
 
-// ---- link previews ----
-//
-// Nothing to trigger any more: the server unfurls a note's URLs in the background
-// after each save (`unfurl_queue.py`) and the preview arrives on a later read. What
-// is left here is removing one you don't want — the editor is the only place with
-// room to offer that, and the card deliberately doesn't.
 async function onFileChange(e: Event) {
   const input = e.target as HTMLInputElement;
   const file = input.files?.[0];
@@ -638,7 +629,10 @@ function revPreview(rev: NoteRevision): string {
           device until you remove it.
         </p>
 
-        <!-- Fetched automatically after each save; removable here and nowhere else. -->
+        <!-- The server unfurls a note's URLs in the background after each save
+             (`unfurl_queue.py`) and the preview arrives on a later read. Removing one
+             happens here and nowhere else: the editor has room to offer it, and the
+             card deliberately doesn't. -->
         <div v-if="liveNote.previews.length" class="flex flex-col gap-2">
           <LinkPreview
             v-for="p in liveNote.previews"
@@ -698,8 +692,8 @@ function revPreview(rev: NoteRevision): string {
             />
           </template>
         </div>
-        <!-- No checklist component. The items are lines of the textarea above, which
-             is what lets a list sit between two paragraphs (M304). -->
+        <!-- No checklist component. The items are blocks above, each one line of the
+             body, which is what lets a list sit between two paragraphs (M304). -->
 
         <div v-if="labelList.length" class="flex flex-wrap gap-1.5 pt-1">
           <span