Bug report: Prime Agent on Windows - three reproducible breakages (with ready fixes)

[samuelbouchard174-ctrl]

Bug report: Prime Agent on Windows — three reproducible breakages (with ready fixes)

Platform: Windows 10 (10.0.19045), Node 24, npm 11, running from a source checkout.

I hit three separate bugs repeatedly on Windows, and worked up fixes for each.
All are small, tested, and live on this branch in my fork:
https://github.com/samuelbouchard174-ctrl/prime-agent/tree/win-fsync-journal-fixes (5 commits, rebased on latest main).

1. Kernel setup always fails on a fresh Windows machine

packages/coding-agent/src/core/kernel/bootstrap.ts resolves the kernel venv
python as path.join(venv, "bin", "python") — the POSIX layout. On Windows the
venv python is Scripts\python.exe. Result: every fresh setup fails with
Failed to set up the Python kernel runtime ... kernel-venv\bin\python, and the
assistant replies empty for every message. Fix: venvPythonPath() helper
(Scripts\python.exe on win32, bin/python elsewhere).

2. Daemon supervisor dies on command journal compaction

command-recovery-journal.ts compact() calls fsyncSync() on a directory
handle, which Windows rejects with EPERM. That repeatedly breaks the daemon
supervisor and the kernel then reports Kernel has been shut down on every tool
call; restarts don't help. Fix: guard the directory fsync to POSIX only.

3. Multi-line pastes become one message per line

Terminals without bracketed-paste support (Windows console/conhost) deliver a
multi-line paste as raw CR/LF bytes. The TUI editor treats each newline as an
Enter keypress, so a 20-line paste becomes 20 submitted prompts (hundreds of
queued messages). Fix (in packages/tui): StdinBuffer wraps raw multi-line
chunks in bracketed-paste markers; Editor/Input treat any text+newline chunk
as paste content instead of submit.

Also included

• run() couldn't spawn .cmd/.bat PATH shims; findExecutable() ignored
  PATHEXT — both fixed (needed to run bootstrap tests on Windows).
• Kernel-bootstrap test suite now passes on Windows (fake uv as a batch file;
  POSIX-only interpreter tests it.skipIf(win32), still run on Linux CI).
• npm run check and the affected suites are green; changelog fragments included.

Happy to split these into separate, discussion-anchored PRs if you'd like them
adopted — they're intended to make Windows a first-class platform.

[samuelbouchard174-ctrl]

hell

[samuelbouchard174-ctrl]

hello i mean