Feat v0.4.3 backlinks wikilinks (#25)

Co-authored-by: Jeffrey Smith <jasafpro@gmail.com>
Co-committed-by: Jeffrey Smith <jasafpro@gmail.com>

CHANGELOG.md

@@ -2,6 +2,47 @@
 
 All notable changes to Switchboard Core are documented here.
 
+## v0.4.3 — Backlinks + Wikilinks
+
+### Added
+
+- **Links table** (`ext_notes_links`): source_id, target_id, link_text columns
+  with indexes on source_id and target_id for bidirectional lookup.
+- **Wikilink extraction**: `_extract_wikilinks()` parses `[[...]]` patterns
+  using `split("[[")` + `find("]]")` (Starlark has no regex or while loops).
+  Returns deduplicated list of link text strings.
+- **Link sync on save**: `_sync_links()` called from `_create_note` and
+  `_update_note` when body changes. Follows the tags delete-all + reinsert
+  pattern. Resolves link text to note IDs via case-insensitive title matching.
+  Unresolved links stored with empty `target_id`.
+- **Cascade delete**: Hard-deleting a note removes both outgoing links
+  (source_id matches) and incoming backlinks (target_id matches).
+- **Link API endpoints**: `GET /links/:note_id` returns outgoing links.
+  `GET /backlinks/:note_id` returns incoming links enriched with source note
+  titles to avoid extra frontend round-trips.
+- **Wikilink preview rendering**: `[[Note Title]]` syntax renders as clickable
+  accent-colored links in the markdown preview. Unresolved wikilinks styled
+  in danger/red with dashed underline.
+- **Wikilink click navigation**: Clicking a resolved wikilink navigates to the
+  target note. Clicking an unresolved wikilink creates the note and navigates
+  to it, then re-saves the source note so the link resolves to blue.
+- **Backlinks panel**: Collapsible panel below the editor showing all notes
+  that link to the current note. Each backlink displays source title and link
+  text. Click to navigate. Hidden when no backlinks exist.
+- **Updated stats**: `/stats` response now includes `links` count.
+
+### Data model
+
+| Table | Columns |
+|-------|---------|
+| `ext_notes_links` | source_id, target_id, link_text |
+
+### Notes package version
+
+0.3.0 → 0.4.0
+
+---
+
 ## v0.4.2 — Tags + Search
 
 ### Added