fix(pty): probe Windows PATH registry via absolute reg.exe

[xianjianlf2]

The Windows in-app terminal refreshes its PATH from the persisted Environment registry keys (HKLM/HKCU) at spawn time, so newly installed CLIs resolve without an app restart (readPersistedWindowsPathSegments → buildPtyHostEnv). That probe shelled out with a bare reg.exe.

When Electron's main process inherits a PATH that omits System32 (Start Menu and service launches), a bare reg.exe through execFileSync/libuv throws ENOENT. node-pty spawns the shell via ConPTY, which always searches System32, so the terminal itself still opens — but the registry probe silently fails (its additions are swallowed by the catch), leaving the in-app terminal on only the stale launch-time PATH. A CLI installed into a directory that a fresh system terminal picks up from the registry — e.g. the Cursor agent CLI — then reports 'agent' is not recognized as an internal or external command, while the exact same command works in a system terminal.

Fix: resolve reg.exe by its absolute System32 path, matching the existing icacls/whoami/cmd handling in win32-utils.ts (added there for this exact stripped-PATH reason).

• Added getRegExePath() to win32-utils.ts.
• windows-environment-path.ts now uses it.
• Unit test asserts the probe invokes the absolute System32 reg.exe, so a stripped Electron PATH still reaches the registry.

This is a correct, codebase-consistent hardening of the registry-refresh path. I could not reproduce on Windows, so I'm referencing rather than closing the issue — a maintainer can confirm it resolves the reporter's exact trigger.

Refs #8834

X: @mark86202384100

[coderabbitai]

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ℹ️ Recent review info

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Configuration used: Repository UI

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Plan: Pro

Run ID: 17259826-e3d6-462d-b63d-2445c09bfd17

📥 Commits

Reviewing files that changed from the base of the PR and between cf02cc4 and 59cae5a.

📒 Files selected for processing (3)

• src/main/pty/windows-environment-path.test.ts
• src/main/pty/windows-environment-path.ts
• src/main/win32-utils.ts

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📝 Walkthrough

Walkthrough

Adds getRegExePath to construct an absolute Windows reg.exe path from SystemRoot, with a fallback to C:\Windows. Updates persisted PATH registry reads to use this helper and adds a test verifying both registry queries use the absolute executable path.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The description explains the fix, but it misses the required template sections for Screenshots, Testing, AI Review Report, Security Audit, and Notes.	Reformat the PR description to match the template and add the missing sections, including screenshots status, testing checklist, AI review, security audit, and notes.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title succinctly and accurately summarizes the main change: using an absolute reg.exe path for the Windows PATH registry probe.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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