Release v7.105.0

Added

• use-nuget --private-cache (or CRATIS_LOCAL_PRIVATE_CACHE=1) gives a consumer worktree its own NuGet package cache, so repacking the same local version is never masked by ~/.nuget/packages. clean removes only local package folders from it, and clean CONSUMER --private-cache removes the whole cache after restore. (part of #885)
• The local package helper records every packed stamp in the feed: producer repository, branch, task and the consumer worktrees using it. list [--json] shows the owner, task, consumers and age of each stamp, and finish --task ID marks a task finished. Pass --task or set CRATIS_LOCAL_TASK when packing. (part of #885)
• clean --expired removes stamps whose tasks are finished, whose consumer worktrees are gone, or whose package has a real release at or above the stamp's version. It never removes a stamp that a live worktree still references, and it checks releases offline unless --online is passed. Dry-run by default. (#885)