Add a bottom-sheet History panel that shows completed jobs in reverse
chronological order with expandable results.
- New history.js module: persists up to 50 jobs in localStorage
(timmy_history_v1), renders rows with prompt/cost/relative-time,
smooth expand/collapse animation, pull-to-refresh and refresh button
- index.html: History panel HTML + CSS (bottom sheet slides up from
bottom edge), "⏱ HISTORY" button added to top-buttons bar
- payment.js: calls addHistoryEntry() when a Lightning job reaches
complete or rejected state; tracks currentRequest across async flow
- session.js: calls addHistoryEntry() after each session request
completes, computing cost from balance delta
- main.js: imports and calls initHistoryPanel() on first init
Fixes#31
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
