fix(settings): widen theme schema to accept custom theme IDs

src/patches/index.ts

@@ -31,6 +31,7 @@ import { DEFAULT_SETTINGS } from '../defaultSettings';
 
 import { writeShowMoreItemsInSelectMenus } from './showMoreItemsInSelectMenus';
 import { writeThemes } from './themes';
+import { writeSettingsTheme } from './settingsTheme';
 import { writeContextLimit } from './contextLimit';
 import { writeInputBoxBorder } from './inputBorderBox';
 import { writeThinkerFormat } from './thinkerFormat';
@@ -212,6 +213,12 @@ const PATCH_DEFINITIONS = [
     group: PatchGroup.MISC_CONFIGURABLE,
     description: 'Your custom themes will be available via /theme',
   },
+  {
+    id: 'settings-theme-schema',
+    name: 'Settings theme schema',
+    group: PatchGroup.MISC_CONFIGURABLE,
+    description: 'Allows custom theme IDs to persist in settings.json',
+  },
   {
     id: 'thinking-verbs',
     name: 'Thinking verbs',
@@ -695,6 +702,15 @@ export const applyCustomization = async (
           JSON.stringify(DEFAULT_SETTINGS.themes)
       ),
     },
+    'settings-theme-schema': {
+      fn: c => writeSettingsTheme(c),
+      condition: !!(
+        config.settings.themes &&
+        config.settings.themes.length > 0 &&
+        JSON.stringify(config.settings.themes) !==
+          JSON.stringify(DEFAULT_SETTINGS.themes)
+      ),
+    },
     'thinking-verbs': {
       fn: c => writeThinkingVerbs(c, config.settings.thinkingVerbs!.verbs),
       condition: !!config.settings.thinkingVerbs,

src/patches/settingsTheme.ts

@@ -0,0 +1,29 @@
+import { globalReplace } from './index';
+
+// CC validates the settings.json `theme` field against built-in enum + "custom:" prefix:
+//   theme:VAR.union([VAR.enum(THEMES),VAR.string().startsWith("custom:").transform(fn)])
+//             .optional().catch(void 0)
+// Tweakcc custom themes have plain IDs (e.g. "winter") that fail both constraints,
+// causing the persisted theme value to be silently reset on every CC startup.
+// Widen the schema to accept any string so custom IDs round-trip through settings.json.
+//
+// CC 2.1.x diff:
+// -theme:h.union([h.enum(k7$),h.string().startsWith("custom:").transform((q)=>q)]).optional().catch(void 0)
+// +theme:h.string().optional().catch(void 0)
+export const writeSettingsTheme = (file: string): string | null => {
+  const pattern =
+    /,theme:([$\w]+)\.union\(\[\1\.enum\([$\w$]+\),\1\.string\(\)\.startsWith\("[^"]*"\)\.transform\(\([^)]+\)=>[^)]+\)\]\)\.optional\(\)\.catch\(void 0\)/;
+
+  let patched = 0;
+  const newFile = globalReplace(file, pattern, (match, zodVar) => {
+    patched++;
+    return `,theme:${zodVar as string}.string().optional().catch(void 0)`;
+  });
+
+  if (patched === 0) {
+    console.error('patch: settingsTheme: failed to find theme schema pattern');
+    return null;
+  }
+
+  return newFile;
+};