Upgrade the solution from .NET 6 to .NET 10

[mohab-elshamy]

This update helps keep the project aligned with the current .NET ecosystem, since .NET 6 has reached end of support from Microsoft. Moving to .NET 10 also improves compatibility with newer SDKs, tooling, NuGet packages, Docker images, and CI environments.

Includes:

• Updated project target frameworks and NuGet packages for .NET 10 compatibility.
• Updated Docker and CI .NET SDK/runtime versions.
• Adjusted Swagger/OpenAPI setup for newer package APIs.
• Updated EF Core usage and added a migration for unique indexes on project routes and tag names.
• Fixed Identity role seed data to avoid noisy migration changes.
• Verified restore/build/test and confirmed no pending EF model changes.

Note:
Please make sure that the JwtSettings:Secret value is at least 32 characters long. The updated JWT package applies stricter validation for the signing secret, so older short secrets that were previously accepted may need to be updated.