fix(tui): gate clampStdoutDimensions behind WSL detection (#35738)

[irandoku]

Problem

clampStdoutDimensions() (PR #35657) patches process.stdout via Object.defineProperty to guard against bogus terminal dimensions (e.g. WSL's 131072×1). However, this breaks TUI layout in Warp terminal — the status bar and input prompt merge onto one line.

Root cause: Warp's process.stdout is not a standard Node TTY stream. The Object.defineProperty override changes how Ink reads terminal dimensions, causing the FlexBox layout inside AlternateScreen to miscalculate vertical space allocation.

Confirmed: WezTerm and other standard terminals are unaffected. Commenting out clampStdoutDimensions() fixes Warp.

Fixes #35738

Fix

Gate clampStdoutDimensions() behind WSL environment detection so it only runs where needed:

if (process.env.WSL_DISTRO_NAME || process.env.WSL_INTEROP) {
  clampStdoutDimensions()
}

Why this works:

• WSL (the motivating case): WSL_DISTRO_NAME / WSL_INTEROP are always set → function runs → bogus 131072×1 is clamped ✅
• Warp / WezTerm / Terminal.app / tmux: env vars unset → no patching → process.stdout untouched → layout works correctly ✅
• No Ink core changes — the function and its behavior are preserved, just conditionally gated
• No split-brain stdout identity — process.stdout remains the canonical object everywhere

Testing

Environment	WSL_DISTRO_NAME	clampStdoutDimensions	Result
WSL	set	✅ runs	131072×1 clamped
Warp (macOS)	unset	❌ skipped	layout correct ✅ (verified by reporter)
WezTerm (macOS)	unset	❌ skipped	layout correct
macOS Terminal.app	unset	❌ skipped	layout correct
tmux in WSL	set	✅ runs	protected

Risk assessment

Minimal. The change is a 3-line conditional guard around an existing function. The function itself is unchanged. The only behavioral difference is that it no longer runs on non-WSL environments — which is the intended fix.

Cross-validated with Codex (GPT-5.5) which confirmed the approach is sound and identified that alternative approaches (replacing process.stdout with a proxy) would break Ink's instances.get(process.stdout) identity lookup.

[alt-glitch]

Competing with #35764 which also fixes #35738. Both approaches gate clampStdoutDimensions() — this PR checks WSL env vars in entry.tsx, while #35764 checks TERM_PROGRAM via an extensible PROBLEMATIC_TERMINALS set in terminalDimensions.ts.

[teknium1]

Thanks for the focused Warp/WSL investigation. This is an automated hermes-sweeper review; the targeted behavior is already absent from current main.

• Commit cd8aa389c9c2b56452bf4fb826c03a4f99a3625e reverted the global clampStdoutDimensions() implementation and deleted ui-tui/src/lib/terminalDimensions.ts.
• Current ui-tui/src/entry.tsx:17-24 has no terminal-dimensions import or clamp invocation, so there is no stdout Object.defineProperty patch for Warp to encounter.
• The revert shipped in v2026.6.5.
• The linked issue fix(tui): clampStdoutDimensions (#35657) breaks TUI layout in Warp terminal #35738 was closed with this same current-main evidence. The separate WSL dashboard resize path is now clamped in hermes_cli/pty_bridge.py:218-235 by fix(dashboard): clamp PTY resize dimensions for WSL2 winsize garbage #38200.