Remove the title field — a note is named by its first line

Operator (note 2897): "notes shouldn't have a title field." The concept of a NAME
stays — search results, export filenames and the command palette all need one —
but nothing is typed into it any more. `display_title` is now the first non-empty
line of the body, falling back to the first checklist item.

That fallback is what step 2 bought, and the reason this could not go first: a
checklist had no body to be named from, so the title was its only name. Now every
note has a body, and a note that is only a checklist is named by its first item.

Gone everywhere: the column and note_revisions.title (0026), the field on the
core's Note/NoteCreateInput/NoteRevision and its SQLite columns (user_version 7),
`normalize_title`, the wire field, the FFI record and `NoteEdit::Title` /
`ClearTitle`, the web editor's "Title (optional)" input and the card's <h3>, and
the Android title field in both the compose sheet and the editor.

**The search vector had to be rebuilt, not just left alone.** `notes.search_vector`
is a STORED GENERATED column whose expression names `title` — Postgres refuses to
drop a column another generated column depends on. It is dropped and recreated over
`display_title` at weight A, which keeps the original intent: a note's NAME ranks
above the rest of its body.

**An imported title becomes the note's first body line.** Keep notes carry one, and
so does any ThoughtSync export taken before this. Dropping it would silently lose
text someone wrote; folding it in puts it exactly where a name now lives, so the
note arrives named as it was. Skipped when the body already opens with that line,
so re-importing an export this code produced doesn't stack duplicates.

Two smaller things fell out. The Android editor loses its bold first field — one
weight throughout, because the first line is the note's name but not a different
KIND of text, which is most of step 4 arriving early. And `ClearTitle`'s
justification comment moved to `ClearRemindAt`, which is now the surviving example
of why NoteEdit is a list rather than a struct of options.

Protocol note corrected to say what actually shipped: v2 is "no kind, no title",
one bump for the pair.

Verified with the local Rust gate this time, not by CI: fmt, clippy and 116 tests
all green before pushing. It caught four things — orphaned serde attributes where
fields were removed, a `wire::Preview.title` I deleted by mistake (a link preview
still has one), nine retention fixtures inserting a dropped column, and four
rustfmt diffs.

frontend/src/components/NoteEditor.vue

@@ -27,7 +27,6 @@ const notes = useNotesStore();
 const config = useConfigStore();
 
 const noteId = ref<string | null>(props.note?.id ?? null);
-const title = ref(props.note?.title ?? "");
 const body = ref(props.note?.body ?? props.initialBody);
 const color = ref<NoteColor>(props.note?.color ?? "default");
 const labelList = ref<NoteLabel[]>(props.note ? [...props.note.labels] : []);
@@ -42,14 +41,13 @@ const fileInput = ref<HTMLInputElement | null>(null);
 const uploadError = ref("");
 
 // Baseline for edit-mode change detection (save only when text actually changed).
-const baseline = ref<{ title: string | null; body: string; color: NoteColor }>({
-  title: props.note?.title ?? null,
+const baseline = ref<{ body: string; color: NoteColor }>({
   body: props.note?.body ?? "",
   color: (props.note?.color ?? "default") as NoteColor,
 });
 
 const isCreate = computed(() => noteId.value === null);
-const hasContent = computed(() => title.value.trim() !== "" || body.value.trim() !== "");
+const hasContent = computed(() => body.value.trim() !== "");
 // Rich features need a saved note; in compose they light up once there's content.
 const richEnabled = computed(() => !isCreate.value || hasContent.value);
 
@@ -57,7 +55,6 @@ const richEnabled = computed(() => !isCreate.value || hasContent.value);
 // template can read attachments/items/remind_at uniformly.
 const draftNote = computed<Note>(() => ({
   id: "",
-  title: title.value.trim() || null,
   display_title: "",
   body: body.value,
   color: color.value,
@@ -96,19 +93,18 @@ watch(
   () => props.note,
   (n) => {
     noteId.value = n?.id ?? null;
-    title.value = n?.title ?? "";
     body.value = n?.body ?? "";
     color.value = (n?.color ?? "default") as NoteColor;
     labelList.value = n ? [...n.labels] : [];
-    baseline.value = { title: n?.title ?? null, body: n?.body ?? "", color: (n?.color ?? "default") as NoteColor };
+    baseline.value = { body: n?.body ?? "", color: (n?.color ?? "default") as NoteColor };
   },
 );
 
 // ---- persistence ----
 async function createFromFields(): Promise<void> {
-  const created = await notes.create({ title: title.value, body: body.value, color: color.value });
+  const created = await notes.create({ body: body.value, color: color.value });
   noteId.value = created.id;
-  baseline.value = { title: created.title, body: created.body, color: created.color as NoteColor };
+  baseline.value = { body: created.body, color: created.color as NoteColor };
 }
 
 // Ensure a persisted note exists (for rich actions mid-compose). Returns its id, or
@@ -135,12 +131,12 @@ async function flush(): Promise<void> {
   }
   const b = baseline.value;
   const nextBody = body.value;
-  const changed = (title.value.trim() || null) !== b.title || nextBody !== b.body || color.value !== b.color;
+  const changed = nextBody !== b.body || color.value !== b.color;
   if (!changed) return;
   saving.value = true;
   try {
-    await notes.saveEdit(noteId.value as string, { title: title.value, body: nextBody, color: color.value });
-    baseline.value = { title: title.value.trim() || null, body: nextBody, color: color.value };
+    await notes.saveEdit(noteId.value as string, { body: nextBody, color: color.value });
+    baseline.value = { body: nextBody, color: color.value };
   } finally {
     saving.value = false;
   }
@@ -148,12 +144,11 @@ async function flush(): Promise<void> {
 
 function resetCompose(): void {
   noteId.value = null;
-  title.value = "";
   body.value = "";
   color.value = "default";
   labelList.value = [];
   checklistOpen.value = false;
-  baseline.value = { title: null, body: "", color: "default" };
+  baseline.value = { body: "", color: "default" };
   uploadError.value = "";
 }
 
@@ -249,12 +244,6 @@ function onBodyKeydown(e: KeyboardEvent) {
   }
 }
 
-function onTitleEnter(e: KeyboardEvent) {
-  e.preventDefault();
-  if (e.shiftKey && isCreate.value) void commitAndContinue();
-  else bodyInput.value?.focus();
-}
-
 // ---- reminder ----
 const reminderLocal = computed(() => toLocalInput(liveNote.value.remind_at));
 async function onReminderChange(e: Event) {
@@ -413,10 +402,9 @@ async function restoreRevisionAt(revId: string) {
   const id = noteId.value;
   if (!id) return;
   const updated = await notes.restoreRevision(id, revId);
-  title.value = updated.title ?? "";
   body.value = updated.body;
   color.value = updated.color;
-  baseline.value = { title: updated.title, body: updated.body, color: updated.color };
+  baseline.value = { body: updated.body, color: updated.color };
   void loadRevisions(); // the pre-restore state became a new revision
 }
 function revLabel(iso: string | null): string {
@@ -424,9 +412,7 @@ function revLabel(iso: string | null): string {
   return new Date(iso).toLocaleString(undefined, { month: "short", day: "numeric", hour: "numeric", minute: "2-digit" });
 }
 function revPreview(rev: NoteRevision): string {
-  const t = (rev.title ?? "").trim();
-  const b = rev.body.trim().replace(/\s+/g, " ");
-  const s = t && b ? `${t} — ${b}` : t || b;
+  const s = rev.body.trim().replace(/\s+/g, " ");
   if (!s) return "(empty)";
   return s.length > 80 ? `${s.slice(0, 80)}…` : s;
 }
@@ -536,14 +522,6 @@ function revPreview(rev: NoteRevision): string {
         </div>
         <p v-if="unfurlError" class="text-xs text-red-600 dark:text-red-400">{{ unfurlError }}</p>
 
-        <input
-          v-model="title"
-          type="text"
-          placeholder="Title (optional)"
-          class="w-full bg-transparent text-base font-semibold outline-none placeholder:text-neutral-400"
-          @keydown.enter="onTitleEnter"
-        />
-
         <textarea
           ref="bodyInput"
           v-model="body"