Agent: bootstrap ErpForFactoryGames.Agent into winget-pkgs so `winget install` works

[ChrisonSimtian]

Problem

winget install ErpForFactoryGames.Agent fails — the package does not exist in microsoft/winget-pkgs (manifests/e/ErpForFactoryGames/ → 404). All the plumbing is in place but the one-time bootstrap was never done.

Current state

• ✅ erp-agent-win-x64.zip ships on every GitHub Release (confirmed on v1.0.25).
• ✅ Multi-file manifest exists at src/Agent/packaging/winget/ — but stale, pinned at PackageVersion: 0.4.45 (ReleaseDate 2026-05-22) with a dead InstallerUrl/InstallerSha256, while latest is v1.0.25.
• ⚠️ CI publish-winget job in .github/workflows/release-images.yml calls wingetcreate update, which can only bump an existing package — it cannot create one. It also early-exits because WINGET_SUBMIT_TOKEN is unset.

Root cause

The manual first submission (wingetcreate submit, documented in src/Agent/packaging/winget/README.md) was never run, so the package isn't in the community repo. Until it is, the CI update job has nothing to update.

Acceptance criteria

• Refresh the three manifests in src/Agent/packaging/winget/ to the current release (version, InstallerUrl, InstallerSha256, ReleaseDate).
• Run the one-time wingetcreate submit from a Windows machine; land the PR in microsoft/winget-pkgs.
• Add repo secret WINGET_SUBMIT_TOKEN (PAT, public_repo scope) so the existing publish-winget CI job auto-bumps on subsequent releases.
• Verify winget search ErpForFactoryGames and winget install ErpForFactoryGames.Agent work end-to-end.

Notes

Needs a Windows box for the wingetcreate submit / winget install --manifest validation. Related to the MSI work in #219 (when the MSI lands, the manifest flips InstallerType: portable → wix, same install command).