Windows schtasks jobs fail with FILE NOT FOUND (bare opencode binary)

[CENFARG]

Description

Jobs scheduled via the schtasks (Windows) backend fail with FILE NOT FOUND because the task action invokes a bare opencode binary that Task Scheduler cannot resolve.

Environment

• OS: Windows 10/11
• Backend: schtasks
• opencode installed via scoop (shim on user PATH)

Field evidence

• Task action using bare opencode in schtasks /TR → Task Scheduler reports LastResult 2147942402 (0x80070002, FILE NOT FOUND); the plugin surfaces ENOENT -4058.
• Scoop shims live in the interactive user PATH, which is invisible to the Task Scheduler session, so the bare name never resolves.
• Same task rewritten with the absolute opencode binary path → LastResult 0, job runs.

Root cause

• findOpencode() (src/index.ts:621) is POSIX-only (which/Unix candidate paths) and falls back to the bare opencode string on Windows.
• The generated schtasks task sets no WorkingDirectory.
• The schtasks backend has no stdout/stderr redirect to the scoped log (launchd/systemd backends have one), so the failure is silent unless you dig up LastResult.

Expected behavior

• Resolve the absolute opencode binary on Windows (scoop shim dir, default install locations, where.exe).
• Set WorkingDirectory on the schtasks task.
• Redirect task output to the scoped log via a cmd wrapper, like the other backends.

A PR with the fix will reference this issue.