Fix question tool version file written as null byte

[zmanian]

Summary

• The Sprites fs/write REST API corrupts very small file uploads -- the 1-byte version file ("3") was being written as a null byte (\0)
• This caused the version check to always fail, triggering a reinstall loop that kept writing the same corrupt version file, blocking chat with "Claude question tool failed to install"
• Fix: write the version file via exec (echo -n '3' > path) instead of the upload API; the server.py upload stays as-is since larger files work correctly

Hardening (new)

• ExecSession now surfaces process exit codes via .exit(code:) event
• runExec success means "exited 0 before timeout" instead of just "didn't time out"
• Installation now fails properly if chmod/version-write step exits non-zero
• Added follow-up verification that server.py is executable and version file matches before reporting success

Investigation

Verified on the bedrock-dev sprite:

• server.py (3896 bytes) was uploaded correctly
• version file contained a single null byte (\0) instead of "3"
• Writing via echo -n '3' > file through exec produces the correct content

Test plan

• Enable Claude Question Tool in Settings
• Start a new chat on a sprite -- tool should install without error
• Verify /home/sprite/.wisp/claude-question/version contains 3 (not a null byte)
• Second chat should skip install (version matches)
• Kill the sprite, start a new chat -- tool should reinstall cleanly
• Verify exit code handling: runExec("false") returns success: false

Generated with Claude Code

[mcintyre94]

That's a weird behaviour from that upload API, thanks for this! Hopefully it doesn't have similar issues for any of our other uploads.