fix: address review nits — atomic write, regex docs, strip test

- scripts/tray-icon-settings.js: _save() now writes to <path>.tmp
  and renameSync's on top of the real file, so a kill mid-write
  can't truncate the settings file. The failure path also unlinks
  the stray .tmp if the write itself threw.
- tests/tray-icon-settings.test.js: add coverage asserting the
  parent directory has only the final file after a save cycle (no
  leftover .tmp).
- scripts/patches/tray.sh: document the [^\]]*? assumption in the
  submenu-strip regex — relies on no radio label containing a
  literal ']'.

All addressed from @aaddrick's PR #491 review.

Co-Authored-By: Claude <[email protected]>

Author: IliyaBrook

scripts/patches/tray.sh

@@ -234,6 +234,9 @@ patch_tray_icon_submenu() {
 const fs = require('fs');
 const p = 'app.asar.contents/.vite/build/index.js';
 let code = fs.readFileSync(p, 'utf8');
+// NB: [^\\]]*? assumes no radio label inside the submenu contains
+// a literal ']' — true for Auto/Black/White today; revisit the
+// regex (e.g. balanced-brace match) if a future label gains one.
 const prevRe = /\\{label:\"Icon color[^\"]*\",submenu:\\[[^\\]]*?\\]\\},/;
 if (prevRe.test(code)) {
   code = code.replace(prevRe, '');

scripts/tray-icon-settings.js

@@ -79,16 +79,23 @@ class TrayIconSettings extends EventEmitter {
     return migrated;
   }
 
+  // Atomic write via <path>.tmp + renameSync so a kill mid-write
+  // can't truncate the settings file — _load() is soft-fail, but
+  // renameSync on POSIX guarantees the reader sees either the old
+  // content or the fully-written new content, never a partial one.
   _save() {
+    const tmp = this._path + '.tmp';
     try {
       fs.mkdirSync(path.dirname(this._path), { recursive: true });
       fs.writeFileSync(
-        this._path,
+        tmp,
         JSON.stringify({ iconMode: this._mode }, null, 2) + '\n',
         'utf8',
       );
+      fs.renameSync(tmp, this._path);
     } catch (e) {
       console.warn('[Tray Icon] Write failed:', e.message);
+      try { fs.unlinkSync(tmp); } catch (_) { /* ignore */ }
     }
   }
 }

tests/tray-icon-settings.test.js

@@ -158,6 +158,20 @@ test('set: persists value to disk', () => {
   } finally { cleanup(tmp); }
 });
 
+test('set: atomic write leaves no leftover .tmp file', () => {
+  const tmp = mkTmp();
+  try {
+    const p = path.join(tmp, 'atomic.json');
+    const s = new TrayIconSettings({ path: p });
+    s.set('black');
+    s.set('white');
+    s.set('auto');
+    const entries = fs.readdirSync(tmp);
+    // Only the final file should exist, never a trailing .tmp
+    assert.deepEqual(entries, ['atomic.json']);
+  } finally { cleanup(tmp); }
+});
+
 test('set: creates parent directory if missing', () => {
   const tmp = mkTmp();
   try {