[Chore] Commit and validate .NET 10 + Aspire 13.2 upgrade

[csharpfritz]

Summary

The spike_DatabasePlugin branch has been upgraded from .NET 9 / Aspire 9.1.0 to .NET 10 / Aspire 13.2.0. Build is green (0 errors, 0 warnings) and all 47 unit tests pass. Changes need to be committed, E2E validated, and merged.

What Changed (39 files)

• global.json -> SDK 10.0.100
• Directory.Build.props -> net10.0 (centralized)
• Directory.Packages.props -> Aspire 13.2.0, Microsoft.* 10.0.x
• Dockerfile -> .NET 10 images
• 22 Razor files: BL0008 fix (= new() -> = default!)
• Security interfaces: Added missing members to IUserManager/ISignInManager + implementations
• Aspire API: Migrated to CommandOptions overload
• Various .NET 10 breaking change fixes

Validation Status

• Build: 0 errors, 0 warnings
• Unit tests: 47/47 pass
• E2E tests: Not yet validated
• Aspire AppHost: Not yet validated
• CI workflows: May need SDK version update

Estimated Effort

2-4 hours for full validation and merge

[csharpfritz]

Triage: Chore (Validation)

Routed to @wash for E2E validation. Status: Build is complete and unit tests pass.

What's done (spike_DatabasePlugin branch):

• Build: 0 errors, 0 warnings
• Unit tests: 47/47 pass
• .NET 10 + Aspire 13.2 upgrade complete

What's pending:

• E2E/Playwright validation
• Aspire AppHost validation
• CI workflow SDK version updates

Priority: 5 (lowest, mostly validation)
Effort: 2-3 hours for E2E; rest is CI/deployment

See PR #352 for the upgrade work.

[csharpfritz]

.NET 10 + Aspire 13.2 upgrade validated. Build clean (0 errors/warnings), 67 unit tests pass (12 plugin + 55 web). Part of PR #352.