v0.15.9

[0.15.9] - 2026-09-10

Fixed

• Windows packaged a3s code TUI smoke: chmod +x the extracted a3s.exe
  before exec, unpack under RUNNER_TEMP, and prefer 7z over unzip.
  v0.15.8 extracted successfully (Smoke binary=/tmp/.../a3s.exe) then Git
  Bash returned 127 on --version because zip/7z left the MSYS executable bit
  unset (the prior Windows -x check exemption never fixed exec). Hermetic
  release_workflow assertions pin chmod, RUNNER_TEMP, and 7z preference.