Term Coder v1.23.2

Fix: the Settings gear (top right) did nothing and logged Script error. — clicking it threw ReferenceError: trustMode is not defined left over from the v1.23.1 module refactor (the settings panel read a bare trustMode that is now IIFE-scoped inside 00-state.js). Settings opens normally again.

Also adds two regression guards so this class of refactor bug (cross-module free identifiers, missing TC exports, missing DOM refs) fails tests instead of shipping.