CLI shell scroll flicker on Windows Terminal / PowerShell #309

Problem

The Squad interactive CLI shell exhibits severe scroll flicker when running in Windows Terminal and PowerShell. The terminal output constantly scrolls and jumps, making the CLI unusable for interactive sessions.

Root Cause

The Ink (React for CLIs) v6.8.0 rendering pipeline has ~16 unsynchronized animation re-renders per second from 6 independent sources, each triggering a full terminal repaint:

Additionally:

• Unstable <Static> keys (array indices) cause Ink to re-render the entire scroll buffer when new items are inserted, shifting all indices
• Live region height toggling between 100% and explicit height causes layout jumps
• Undebounced resize handlers fire rapid bursts of re-renders during terminal resize

Additional Issues Found

During investigation, three pre-existing test failures were discovered:

1. test/marketplace.test.ts — Uses /nonexistent as a guaranteed non-existent path, but on Windows Node.js resolves this to D:\nonexistent (root of current drive), which can exist
2. scripts/bump-build.mjs — Produces 4-part versions like 0.8.25.4 for non-prerelease builds, which npm rejects as invalid semver during npm install of packed tarballs
3. test/cli-packaging-smoke.test.ts — Fails because the full test suite triggers prebuild which mutates package.json versions via bump-build.mjs

Environment

• Windows 11 + Windows Terminal + PowerShell 7
• Node.js 22.x
• Ink v6.8.0, React 19
• Squad CLI v0.8.25