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/notes/markdown.ts

@@ -2,12 +2,12 @@
 // stays plain text; this only formats what's shown. We render the parsed tree as
 // Vue vnodes (never v-html), so there is no HTML-injection surface. Deliberately a
 // small subset — headings (#..###), unordered/ordered lists, blockquote, fenced
-// code, and inline **bold** / *italic* / _italic_ / `code` — plus ThoughtSync's own
-// [[wiki-links]]. Note: headings need a space after `#`, so a #tag (no space) is
-// left as plain text and never mistaken for a heading.
+// code, and inline **bold** / *italic* / _italic_ / `code`. Note: headings need a
+// space after `#`, so a #tag (no space) is left as plain text and never mistaken for
+// a heading.
 
 export interface InlineToken {
-  type: "text" | "bold" | "italic" | "code" | "link";
+  type: "text" | "bold" | "italic" | "code";
   value: string;
 }
 
@@ -19,9 +19,13 @@ export interface Block {
   value?: string;
 }
 
-// Order matters: links + code are matched before emphasis so their contents aren't
-// re-parsed; bold (**) before italic (*). Emphasis does not nest (v1).
-const INLINE_RE = /(\[\[[^[\]]+\]\])|(`[^`]+`)|(\*\*[^*]+\*\*)|(\*[^*]+\*)|(_[^_]+_)/g;
+// Order matters: code is matched before emphasis so its contents aren't re-parsed;
+// bold (**) before italic (*). Emphasis does not nest (v1).
+//
+// `[[wiki-links]]` used to lead this alternation. They are gone (note 2897) — this is
+// a capture-and-recall surface, and a linking system is organization. `[[text]]` now
+// renders as the literal characters someone typed, which is what it always was.
+const INLINE_RE = /(`[^`]+`)|(\*\*[^*]+\*\*)|(\*[^*]+\*)|(_[^_]+_)/g;
 
 export function parseInline(text: string): InlineToken[] {
   const tokens: InlineToken[] = [];
@@ -31,9 +35,8 @@ export function parseInline(text: string): InlineToken[] {
   while ((m = INLINE_RE.exec(text)) !== null) {
     if (m.index > last) tokens.push({ type: "text", value: text.slice(last, m.index) });
     const raw = m[0];
-    if (m[1]) tokens.push({ type: "link", value: raw.slice(2, -2).trim() });
-    else if (m[2]) tokens.push({ type: "code", value: raw.slice(1, -1) });
-    else if (m[3]) tokens.push({ type: "bold", value: raw.slice(2, -2) });
+    if (m[1]) tokens.push({ type: "code", value: raw.slice(1, -1) });
+    else if (m[2]) tokens.push({ type: "bold", value: raw.slice(2, -2) });
     else tokens.push({ type: "italic", value: raw.slice(1, -1) });
     last = m.index + raw.length;
   }