v1.6.1 — fix bilingual toggle

v1.6.1 — fix: bilingual toggle now translates the whole UI

Bug fix — clicking EN/ΕΛ previously only switched the static labels; tabs, manuscript chips, story-memory hints and co-author POVs stayed in the old language until reload. Now the toggle re-renders the entire interface instantly (via a full refresh), with a resilient fallback so it can never be blocked by a glitch.

Verified: 59/59 test suite + dedicated toggle checks (labels, tabs, chapter chips, status, co-author, memory) pass in both directions.