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.

tests/test_notes.py

@@ -7,7 +7,6 @@ from thoughtsync.common import coerce_bool, parse_dt
 from thoughtsync.models.note import NOTE_COLORS, Note
 from thoughtsync.notes import (
     _attachment_ext,
-    _escape_like,
     _header_filename,
     _keep_spec,
     _native_spec,
@@ -19,7 +18,6 @@ from thoughtsync.notes import (
     next_occurrence,
     normalize_color,
     normalize_recurrence,
-    parse_link_titles,
     parse_list_items,
     parse_tags,
 )
@@ -40,7 +38,7 @@ def test_all_note_routes_registered(app):
         for name in (
             "list_notes", "search_notes", "list_reminders", "complete_reminder",
             "snooze_reminder", "export_notes", "import_notes", "list_titles",
-            "link_search", "note_backlinks", "reorder_notes", "create_note",
+            "reorder_notes", "create_note",
             "get_note", "update_note", "list_revisions", "restore_revision",
             "set_note_labels", "add_item", "update_item", "delete_item",
             "reorder_items", "upload_attachment", "get_attachment",
@@ -117,32 +115,11 @@ async def test_reorder_requires_auth(app):
     assert resp.status_code == 401
 
 
-def test_parse_link_titles():
-    titles = parse_link_titles("see [[Alpha]] and [[ beta ]] and [[Alpha]] again")
-    assert titles == ["alpha", "beta"]
-
-
-def test_parse_link_titles_empty():
-    assert parse_link_titles(None) == []
-    assert parse_link_titles("no links here") == []
-
-
-# `rewrite_link_title` and `_rename_inbound_links` are gone (M13 step 1). They kept
-# backlinks alive across a rename by editing the [[text]] inside every note that
-# linked to the renamed one — which meant one note's edit silently rewrote another's
-# words. Links are bound to a note id now, so a rename needs no repair at all.
-#
-# What replaced them (`_resolve_target`, `_claim_unresolved_links`, and the id-first
-# resolution in backlinks / the graph / serialization) is all SQL, and this suite runs
-# without a database, so it is deliberately not asserted here. See the task log: that
-# behaviour was checked by hand, and this repo has no integration lane to hold it.
-
-
-def test_parse_link_titles_ignores_nesting():
-    # The link regex refuses [ and ] inside a token, so a malformed nest yields the
-    # inner name rather than something spanning both — worth pinning, since this is
-    # the string that becomes a link's stored target.
-    assert parse_link_titles("[[outer [[inner]] ]]") == ["inner"]
+# [[wiki-links]] are gone entirely (note 2897), and with them backlinks, the graph,
+# the name index and the `[[` autocomplete. So are the two helpers that used to keep
+# links alive across a rename, and the id-binding that briefly replaced them. Nothing
+# here asserts their absence — `test_all_note_routes_registered` below is what would
+# notice a route coming back, and the removal is one commit rather than a fossil.
 
 
 def test_derive_display_title_explicit_wins():
@@ -188,14 +165,6 @@ def test_parse_list_items():
     assert parse_list_items([1, "x", None, {"a": 1}]) == ["x"]
 
 
-def test_escape_like():
-    # LIKE wildcards in user input must be neutralized so they match literally.
-    assert _escape_like("100%") == "100\\%"
-    assert _escape_like("a_b") == "a\\_b"
-    assert _escape_like("c:\\path") == "c:\\\\path"
-    assert _escape_like("plain") == "plain"
-
-
 def test_parse_dt():
     # A full ISO instant round-trips (used to validate the Timeline date range).
     d = parse_dt("2026-07-19T12:30:00+00:00")
@@ -217,18 +186,6 @@ async def test_titles_requires_auth(app):
     assert resp.status_code == 401
 
 
-async def test_link_search_requires_auth(app):
-    client = app.test_client()
-    resp = await client.get("/api/notes/link-search?q=hi")
-    assert resp.status_code == 401
-
-
-async def test_graph_requires_auth(app):
-    client = app.test_client()
-    resp = await client.get("/api/graph")
-    assert resp.status_code == 401
-
-
 async def test_reminders_requires_auth(app):
     client = app.test_client()
     resp = await client.get("/api/notes/reminders")