Remove [[wiki-links]], backlinks and the graph

Operator, 2026-08-22 (note 2897): ThoughtSync is an intermediary surface. You
write here because it's easy — a notebook in your pocket — and later you recall
the thing and go finish it somewhere else. Recall is the product; organization
is secondary. A linking system is organization, and it isn't what this is for.

So: `[[wiki-links]]`, backlinks, the `[[` autocomplete, the note_links table,
`/api/notes/link-search`, `/api/notes/<id>/backlinks`, the whole graph blueprint
and GraphView. Rust core loses `extract_links`, `backlinks`, `link_search` and
`create_titled`; the desktop loses the three Tauri commands that exposed them.

This subsumes 982d24c rather than reverting it. That commit bound links to a
note id so a rename would stop rewriting other notes' bodies — real infra, but
infra for a feature that is now gone, and nothing it added survives. Alembic
0023 stays in the chain anyway: it shipped in an image and may already be
applied, and deleting an applied revision strands a database's version pointer.
0024 drops the table and takes the column with it. The history stays honest
about the fact that it existed for a day.

Two things deliberately kept, because they were serving recall and only
incidentally serving links:

- `/api/notes/titles` and the titles store. The command palette lists them so
  you can jump to a note by name. `resolve()` — the name→note lookup that only
  linking needed — is gone.
- `display_title`. Every note still has a name for search results and export
  filenames. What that name is FOR changed; that it exists did not.

`notes/links.py` is now `notes/tags.py`, holding the #tag→label reconciliation
it always also owned. A file called links.py with no links in it would have been
exactly the drift this removal is meant to end.

Also swept out on the way: `_escape_like`, whose only caller was link-search,
and the `graph` icon. Nothing lost that a person typed — note_links was always
derived, and the `[[text]]` is still sitting in every body it was written in.

frontend/src/components/AppShell.vue

@@ -49,7 +49,6 @@ const shortcuts = [
   { label: "New note (or just start typing)", keys: ["Enter", "c"] },
   { label: "Search", keys: ["/"] },
   { label: "Go to Board", keys: ["g", "b"] },
-  { label: "Go to Graph", keys: ["g", "g"] },
   { label: "Go to Reminders", keys: ["g", "r"] },
   { label: "Go to Timeline", keys: ["g", "t"] },
   { label: "Browse cards", keys: ["↑", "↓", "←", "→"] },
@@ -121,11 +120,6 @@ function onKeydown(e: KeyboardEvent) {
       void router.push("/");
       return;
     }
-    if (e.key === "g") {
-      e.preventDefault();
-      void router.push("/graph");
-      return;
-    }
     if (e.key === "r") {
       e.preventDefault();
       void router.push("/reminders");
@@ -207,7 +201,7 @@ watch(
  *
  * Keyed off the route name rather than each view declaring its own title, so the
  * label sits in one place and can't go missing (the board and search never had one)
- * or drift in styling (timeline, reminders and graph each had their own h1).
+ * or drift in styling (timeline and reminders each had their own h1).
  *
  * A label lens is named by the label itself — "Groceries" is what the user came
  * looking for; "Label" would tell them nothing they didn't already know.
@@ -224,8 +218,6 @@ const lensName = computed<string>(() => {
       return "Timeline";
     case "reminders":
       return "Reminders";
-    case "graph":
-      return "Graph";
     case "label":
       // The store may not have loaded yet on a deep link; fall back rather than
       // flashing an empty slot.
@@ -403,9 +395,6 @@ async function signOut() {
           <RouterLink to="/" class="nav-link" :class="route.name === 'board' ? 'nav-link-active' : ''">
             <Icon name="note" /> Notes
           </RouterLink>
-          <RouterLink to="/graph" class="nav-link" :class="route.name === 'graph' ? 'nav-link-active' : ''">
-            <Icon name="graph" /> Graph
-          </RouterLink>
 
           <div class="mt-3 flex items-center justify-between px-3 pb-1">
             <span class="text-xs font-semibold uppercase tracking-wide text-neutral-400">Labels</span>
@@ -522,7 +511,7 @@ async function signOut() {
            BoardView, so keying on the route would remount it — blanking the board
            and refetching, which is precisely the page-change feeling this is meant
            to remove. Unkeyed, Vue only transitions when the component TYPE changes
-           (board ↔ search ↔ timeline ↔ graph), and moving between the board's own
+           (board ↔ search ↔ timeline), and moving between the board's own
            lenses stays an in-place reflow that NoteGrid animates. -->
       <main id="main" tabindex="-1" class="min-w-0 flex-1 focus:outline-none">
         <RouterView v-slot="{ Component }">