fix: wrap composer input across multiple lines

[dsilbergleithcu-godaddy]

Summary

Fixes #1. In Read Mode, typing past the terminal width truncated the input and hid the cursor. The composer now wraps onto additional visual rows and the footer grows to accommodate it.

Changes

• wrapInput(text, cursor, wrapWidth) — character-based wrap that also reports (cursorRow, cursorCol). Handles the two awkward cases:
  • cursor sitting exactly on a wrap boundary → next line, col 0
  • cursor at end of a full-width last line → fresh empty trailing line
• Dynamic footer — replaced fixed FOOTER_LINES = 5 with FOOTER_STATIC_LINES = 4 + inputVisualLines. vh() / maxScroll() now reflect the real viewport so PgUp/PgDn still page correctly.
• Continuation indent — wrapped rows start with two spaces so they line up under the > prompt.
• Render order: the input is wrapped before vh() is read, so the viewport/footer split is correct on the same frame the input grows or shrinks.

I went with character-based wrap rather than word-boundary wrap. It makes cursor mapping exact for any input (including paste, long URLs, CJK) and avoids edge cases around whitespace-only segments. Happy to add word-boundary wrapping on top if you'd prefer — the hooks are all in one function.

Tests

Added test/wrap-input.test.ts with 9 focused tests (one assertion each) covering: short text, exact width, long wrap, cursor at start, cursor mid-line, cursor at wrap boundary, cursor at end of full text, cursor at end of partial line, empty text. I also did a break-the-code check (inverted the wrap condition) and confirmed 3/9 failed before restoring.

Run: npx tsx --test test/wrap-input.test.ts

Not covered

• Composer that wraps taller than the terminal itself — content clips at the bottom edge. Could be addressed in a follow-up by scrolling the composer independently.
• Word-boundary breaking — intentionally omitted; see summary.