[codex] Add workflow profile editor

[nickbeau]

Closes #57.

Summary

• Adds workflow profile mutation contracts, domain revision/default metadata, and SQLite persistence with migration support.
• Adds the Workflow Profiles editor page and repository import profile selection.
• Documents workflow profile management and covers the new behavior with domain, persistence, and Blazor tests.

Validation

• dotnet build Conductor.slnx --no-restore
• dotnet test Conductor.slnx --no-build