Prepare Win-CodexBar 0.43.0

[Finesssee]

Summary

Prepare Win-CodexBar 0.43.0 for packaging.

• Bump marketing version to 0.43.0 / build 86 in version.env, Cargo crates, package.json, and tauri.conf.json
• Add Windows changelog for sub2api, Factory API Auto, Kimi CLI reuse, account-scoped notifications, cost-scan freshness, FloatBar fixes, and localization work since 0.42.0

Release follow-up (after merge)

1. Tag v0.43.0
2. scripts\windows-release-build.ps1 -Ref v0.43.0 -RepoUrl https://github.com/nesszer/Win-CodexBar.git -SmokeInstall
3. Create GitHub release and upload Setup/portable + sha256 sidecars
4. Winget manifest update once the installer URL is stable

Test plan

• scripts\release-doctor.ps1 -Version 0.43.0 -SkipGitHub version consistency OK
• Tag + release build assets
• Smoke install