Release: bump to 1.0.0 and publish to PSGallery

Part of #120 (Phase 5 — Release). This is the destination.

Scope

• Bump ModuleVersion to 1.0.0 in PowerShellBuild.psd1
• In the same commit, point the PSData URLs (LicenseUri, IconUri, ReleaseNotes) at /main/ rather than /master/. There is no master branch; those links resolve today only through GitHub's branch-rename redirect.
• Cut the 1.0.0 GitHub Release. Publishing it triggers .github/workflows/publish.yaml, which runs the full test suite and then Publish-Module with the PSGALLERY_API_KEY repository secret — the path that published 0.8.0, 0.8.1 and 0.8.2.

Cut 1.0.0-rc1 and soak ≥ 7 days — dropped 2026-09-04. The install-time risk the rc existed for is covered two other ways: Publish-Module itself refuses to publish a package whose RequiredModules cannot be resolved on the destination repository, so an unsatisfiable dependency fails the release rather than reaching consumers; and #229 installs the built module from a local repository in CI on both editions. What the rc uniquely offered was consumer exposure, which prerelease build tooling does not get in practice. Recorded on #120.

Pre-flight before tagging

• #159 closed — the guide's coherence pass and the 1.0.0 changelog entry
• #229 green on main
• A workflow_dispatch run of publish.yaml against main has completed — done 2026-09-04, run 33914510553: checkout@v7, bootstrap, and the psake chain Init Clean Build Analyze Pester all ran on the ubuntu runner (558 passed, 0 failed, 33 Windows-only skips), and the only failure was Publish-Module refusing 0.8.2 as already published on the gallery. The manual-trigger recovery path is therefore proven too. It exercises checkout v7 (first use since #214), bootstrap and the full suite on the runner, and is expected to fail only at Publish-Module because 0.8.2 already exists on the gallery — the whole workflow proven except the upload, at zero risk. The manual trigger failed the one time it was used and its logs have expired, so this also verifies the recovery path in advance.

Gate

Blocked on the release documentation being final. Everything else in the map must be closed or explicitly ruled out of scope before this opens.

Definition of done (from #120)

• Every in-scope item is closed
• The Phase 4 milestone discrepancy is resolved — #94 and #95 unmilestoned during charting and since closed. #98 and #103 were restored to v1.0.0 on 2026-08-28 and now block this issue: they are the only two public functions without coverage of their own, and the compile-mode test that appeared to cover Build-PSBuildModule asserts on file text only, so it passes over a module that exports nothing (#201)
• Every public function has coverage of its own, and #201 is resolved
• The migration guide is complete and the AI prompt is tested against a sample consumer build.ps1
• 1.0.0-rc1 has soaked ≥ 7 days with no blocker reports

Done when

PowerShellBuild 1.0.0 is on PSGallery. The map is complete.

Start with PowerShellBuild.psd1 and .github/workflows/publish.yaml, then verify the pre-flight dependencies #159, #229, #98, #103, and #201 before changing release metadata. Confirm the documentation and coverage gates are complete, then create the 1.0.0 GitHub Release so the workflow publishes the module to PSGallery. Done means PowerShellBuild 1.0.0 is available on PSGallery and the release map is complete.