[codex] Fix Windows daemon console probe hang

[mariusvniekerk]

Summary

• switch Windows daemon StartDetached back to DETACHED_PROCESS so daemon startup does not expose CONIN$ to terminal probes
• move CREATE_NO_WINDOW to non-interactive git/cmd subprocess creation, including safe-directory config probes
• add Windows regression tests for daemon console input exposure and git subprocess window hiding while preserving TerminalPrompt=true

Root Cause

PR #14 moved detached daemons from DETACHED_PROCESS to CREATE_NO_WINDOW to prevent visible console flashing from console-subsystem descendants. That gives the daemon a hidden live console, so libraries that probe terminal state can open CONIN$ and block waiting for terminal replies during startup.

This keeps daemons console-less and applies hidden-window behavior at the known non-interactive git spawn sites instead.

Fixes #19.

Validation

• go test ./...
• go vet ./...

[roborev-ci]

roborev: Combined Review (b99afa2)

No issues found.

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Panel: ci_default_security | Synthesis: codex | Members: codex_default (codex/default, done, 4m2s), codex_security (codex/security, done, 32s) | Total: 4m34s

[roborev-ci]

roborev: Combined Review (1deaffe)

No issues found.

---

Panel: ci_default_security | Synthesis: codex | Members: codex_default (codex/default, done, 4m2s), codex_security (codex/security, done, 41s) | Total: 4m43s