Feature/copilot passthrough p2

[berthertogen]

• Update sample apps to use local project references
• Refactor API sample to reuse a DI-managed Printer
• Initialize Printer once at app startup (not per request)
• Fix README script naming/instructions to match repo reality
• Build + test to confirm no regressions

Closes #80

[Copilot]

Pull request overview

Updates the sample applications to reference the local Weasyprint.Wrapped project and refactors the API sample to reuse a DI-managed Printer that is initialized once at startup, while also aligning README instructions with current script names.

Changes:

• Replaced NuGet package references in sample apps with local ProjectReferences.
• Refactored ExampleApi to inject a singleton Printer and initialize it once during app startup.
• Updated README to reference build-on-linux.sh and adjusted sample-running guidance.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/Weasyprint.Wrapped.ExampleApi/Weasyprint.Wrapped.ExampleApi.csproj	Switches API sample from package reference to project reference.
src/Weasyprint.Wrapped.ExampleApi/Program.cs	Registers Printer as a singleton and initializes it at startup.
src/Weasyprint.Wrapped.ExampleApi/Controllers/PrintController.cs	Fixes logger generic type and injects/reuses DI-managed Printer.
src/Weasyprint.Wrapped.Example/Weasyprint.Wrapped.Example.csproj	Switches console sample from package reference to project reference.
readme.md	Updates Linux build script name and revises sample-running instructions.