fix(terminal): rejoin user prompts the PTY wrapped with an indent

[RonenMars]

Problem

A long prompt renders in the terminal view as two unrelated transcript lines, split mid-sentence.

The split itself is not ours to remove: the streamer spawns the PTY at a fixed PTY_COLS = 120 with no resize protocol, so Claude Code word-wraps its own render at 120 columns and emits each wrapped row separately.
lib/collapseWrappedUserLines.ts exists precisely to stitch those rows back together using the user_message text the streamer sends as ground truth, and it silently failed to fire.

Verified state

Measured against the reported session on 2026-08-12: the first row is ❯ plus 116 characters = 118 columns, and continuing with the next word would need 122 — over 120, so the CLI wrapped and indented the continuation row.

Two whitespace holes stopped the rejoin, both reproduced before the fix:

• collapseWrappedUserLines.ts:34 joined rows with ' ' + lines[j] untrimmed, but VirtualTerminal.getRawLines() only trimEnd()s — the continuation row's leading indent survived into the joined string and broke the exact-string comparison.
• collapseWrappedUserLines.ts:23 matched the ❯ prefix against the untrimmed row, so any left padding on the prompt row stopped the collapse before it started. isUserLine in TerminalOutput.tsx:39 trims first, so the two disagreed about what a user row is.

Neither shape was covered — every fixture in the existing suite used unindented continuation rows.

Change

Compare joined rows against the ground truth on collapsed whitespace, and match the prompt prefix on the trimmed row.
The collapsed row now emits the ground-truth string verbatim instead of the space-joined reconstruction, which also restores prompts that were typed with newlines — broken before for the same reason.

Deliberately unchanged: PTY_COLS stays at 120, and wrapping of non-user output (tool results, trees, tables) is still left alone, since the rejoin only engages on an exact user_message match.

Tests

Three regression cases added — indented continuation row (using the reported prompt verbatim), left-padded prompt row, and a newline-bearing prompt.

npx jest --ci --runInBand __tests__/unit/lib/collapseWrappedUserLines.test.ts → 10 passed.
npx jest --ci --runInBand --testPathPattern "TerminalOutput|TerminalView" → 26 passed.
npx tsc --noEmit clean on the changed files, npx eslint clean.