Point the scenarios at the package ids and version line that actually ship

[ChrisonSimtian]

Fixes all three canary scenarios. They were red for two unrelated reasons.

What changed

• minimal + transition-shims float at 10.*-* instead of 2026.1.*-*. The 2026.1.x line was retired when the repo moved back to 10.x, and the last 2026.1.0 prereleases have since been deleted from the feed, so the range had no candidates and restore failed with NU1102. 10.*-* tracks the whole 10.x line, so it survives 10.4 → 10.5 without an edit. Floating is kept on purpose, per the locked decision in docs/DESIGN.md.
• tool-manifest tracks Fallout.GlobalTool (singular) and reports on fallout.globaltools as retired. The two roles were the wrong way round.
• The tool-list assertion is now ^fallout\.globaltool[[:space:]]. The old prefix match would have accepted the plural id and passed against the wrong package.
• Dropped the stale fallout.globaltools source mapping. Fallout.* already routes the tool to the GitHub Packages feed.
• Updated README.md, docs/DESIGN.md, Directory.Build.props and the scenario README, which all still quoted 2026.1.*-* or the plural id.

Why the tool ids were inverted

Fallout-build/Fallout#575 recorded the rename Fallout.GlobalTool → Fallout.GlobalTools, and this scenario was built to guard it. The rename was then reverted: Fallout.Cli.csproj sets <PackageId>Fallout.GlobalTool</PackageId> again. The plural id got exactly one nuget.org release, 10.4.0-rc.4, which has since been unlisted — so dotnet tool update Fallout.GlobalTools --prerelease had nothing to resolve. This is the regression the scenario exists to catch, just in the direction nobody expected.

Verification

Ran all three scenarios locally against the live feeds, not just inspected:

minimal            Fallout.Common/10.4.1-preview.1.g9467569f76   restore OK
transition-shims   Nuke.Common/10.4.1-preview.1.g9467569f76      restore OK
tool-manifest      fallout.globaltool 10.4.0                     update + restore + tool list OK

Both package scenarios resolve the current head of main. The tightened assertion was checked both ways: it matches the singular id and rejects the plural.

canary.yml parses as YAML; every edited XML and JSON file parses. No 2026.1 reference remains in the repo.

Notes

• tool-manifest was already failing before the feed cleanup — it reads nuget.org only, so the deletions never affected it. minimal and transition-shims were green on 2026-08-17 and broke when the 2026.1.0 prereleases were removed.
• The retired-id deprecation reporting step still passes continue-on-error: true, so it reports without failing the scenario. Deprecating the retired ids on nuget.org is still the manual action tracked in Fallout-build/Fallout#575.