Release 0.18.3: prompt history and pointer-aware wheel scrolling

[mostlydev]

Fixes the 0.18.2 regression and adds pointer-aware wheel scrolling.

Summary

• Up/Down recall submitted prompts again at an empty draft, and still choose suggestions or move through multi-line drafts. Ctrl+P / Ctrl+N also recall prompts.
• With --mouse, SGR wheel events are routed by their exact row: over the conversation they scroll history, over the composer they move through the draft or prompt history. Fixed bars are ignored.
• No guessing from arrow-key chunks; the default mode keeps native text selection with keyboard scrolling.

Verification

• npm run typecheck, npm test (575 passed, 1 skipped), npm run build, git diff --check
• Live: an injected wheel event over the transcript scrolled history with the draft untouched; over the composer it recalled a prior prompt.