📝 Note the widened-string-union matcher test

backlog.tasks

@@ -37,6 +37,8 @@ Testing:
     ✔ Rewrite `src/util/__tests__/lsp-completion.ts` onto `createMessageConnection` and typed requests @done
     ✔ Update `development/testing.md § Autocomplete` for the new client @done
     ✔ Run `npm run verify` and check the task off @done
+☐ Test a literal union widened with `(string & {})` — `"red" | "green" | "yellow" | (string & {})` @medium
+    → autocomplete should still offer the literals; arbitrary strings stay assignable and fall through to the fallback
 
 Matcher:
 ✔ Clean up: adopt the 3-overload matcher (`src/prototype-ac2.ts`) and delete the prototypes @high @done