[codex] Handle Windows Codex internal versions

[Wangnov]

Summary

• Parse mirror schema v3 Windows metadata as two versions: Codex app version for UI/update semantics and MSIX package version for package identity.
• Read installed Windows Codex internal version from resources/app.asar/package.json for MSIX and portable installs, with package-version fallback when unreadable.
• Keep MSIX verification bound to the package version and package moniker, and reject unavailable requested architectures instead of silently falling back to x64.

Root Cause

The mirror now groups releases by the Codex internal app version while Windows MSIX assets still use a separate four-part package version. Manager was treating sources.windows.architectures.*.version as the user-facing latest Codex version, so Windows could show package versions such as 26.623.5546.0 instead of internal versions such as 26.623.42026.

Validation

• cargo test in crates/codex-win-engine
• cargo test -p codex-app-manager in src-tauri
• npm run check
• npm run test
• git diff --check