[Bug]: Windows reports every provider CLI not found even when they are on User PATH

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/desktop

Steps to reproduce

1. On Windows, install any T3 provider CLI so it is on User PATH (winget, official irm installer, npm). Confirm a new PowerShell window can run it (Get-Command opencode, grok, codex, cursor-agent, …).
2. Launch T3 Code from the desktop shortcut / Start Menu (not from that shell).
3. Open Settings → Providers.

Expected behavior

Each installed CLI is found (opencode, grok, codex, cursor-agent, claude, …) without setting an absolute binaryPath.

Actual behavior

Every local provider stays red / Not found, even when the same binaries were on User PATH before T3 was installed. A refreshed PowerShell session finds them. Restarting T3 does not help.

This is Windows-only. Electron inherits a stale process PATH. The Windows environment probe uses [Environment]::GetEnvironmentVariable('PATH') (process env), not User/Machine registry. macOS/Linux login-shell probing is a different path and is not this bug.

On this machine the CLIs are present:

cursor-agent → %LOCALAPPDATA%\cursor-agent\cursor-agent.cmd
opencode     → %LOCALAPPDATA%\Microsoft\WinGet\Links\opencode.exe
grok         → %LOCALAPPDATA%\Microsoft\WinGet\Links\grok.exe
codex        → %LOCALAPPDATA%\Microsoft\WinGet\Links\codex.exe

T3 looks for cursor-agent, opencode, grok, codex, and claude. User PATH includes %LOCALAPPDATA%\Microsoft\WinGet\Links and %LOCALAPPDATA%\cursor-agent.

Impact

Major degradation or frequent failure

Version or commit

Current Windows desktop (reproduced 2026-08-17)

Environment

• OS: Windows 11 (Build 26200)
• Shell: PowerShell 7
• T3 Code desktop Settings → Providers
• Provider CLIs on User PATH via WinGet Links and the official Cursor CLI installer

Workaround

Set each provider binaryPath to the absolute executable, or launch T3 from a shell whose process PATH already includes User PATH.

Related

• #4846 (closed) — same stale User PATH probe; Claude was papered over by adding ~\.local\bin
• #6352 — mid-session install + Refresh still misses a newly added User PATH entry
• #4569 — adds %LOCALAPPDATA%\cursor-agent in packages/shared only

Start with the Windows environment probe that calls [Environment]::GetEnvironmentVariable('PATH') and trace how its result is used by Settings → Providers. Compare the process PATH with User and Machine PATH handling, then verify that the listed provider CLIs are found after launching from the desktop shortcut and after Refresh.