Major changes:
- Replace alternate screen buffer + app-side mouse tracking/virtual scroll
with normal screen buffer + Ink <Static> for permanent scrollback.
Terminal's native scroll/selection/copy just works — no mouseInput.ts needed.
- Fix burn rate (🔥) to use model response time (modelTimeMs) instead of
session elapsed time, so it reflects actual generation throughput.
- Upgrade dependencies: openai 6→7, commander 13→15, execa 9→10, vitest 3→4,
node types 22→26, tsup target node20→node22.
- Update upgrade memo with current architecture, all completed upgrades,
and working tree status.
kim