feat(electron): main process, vault, search index, links, import, capture

Vault on plain .md files with FTS5 index, link rewriting, canvas files,
history/trash/backup, link previews, image fetch, tasks and unlinked
mentions, Notion/Obsidian importer, quick-capture window and shortcut.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

electron/settings.cjs

@@ -0,0 +1,39 @@
+'use strict';
+// App settings (not notes): last vault, theme, window size, folded pages.
+const fs = require('node:fs');
+const path = require('node:path');
+
+let file = null;
+let cache = null;
+
+function location() {
+  if (!file) file = path.join(require('electron').app.getPath('userData'), 'settings.json');
+  return file;
+}
+
+function get() {
+  if (cache) return cache;
+  try { cache = JSON.parse(fs.readFileSync(location(), 'utf8')); } catch { cache = {}; }
+  return cache;
+}
+
+let timer = null;
+function set(patch) {
+  cache = { ...get(), ...patch };
+  clearTimeout(timer);
+  timer = setTimeout(flush, 200);
+  return cache;
+}
+
+function flush() {
+  clearTimeout(timer);
+  if (!cache) return;
+  try {
+    fs.mkdirSync(path.dirname(location()), { recursive: true });
+    fs.writeFileSync(location(), JSON.stringify(cache, null, 2));
+  } catch (err) {
+    console.error('Could not write settings', err);
+  }
+}
+
+module.exports = { get, set, flush };