Add Resolve delegate support to generator

[AlonTalmi]

Summary

• add Resolve and NamedResolve delegates so generated containers can provide resolver delegates
• update known types, call site generation, and diagnostics to emit delegates and errors when registrations are missing
• document the new analyzer rules and add unit tests covering success and failure scenarios for resolve delegates

Testing

• dotnet test src/Jab.Tests/Jab.Tests.csproj (fails: dotnet executable not available in environment)

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Codex Task

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Make Resolve delegate parameterless

Resolve<T> is declared with a string name parameter, identical to NamedResolve<T>, even though the generator emits the delegate for unnamed services and never forwards a name (see the lambda _ => GetService<T>()). As a result, consumers must supply a dummy string argument (resolver("ignored")) and cannot use the natural parameterless invocation (resolver()), and any name they pass is silently ignored. This makes the new API unusable for its intended lazy resolution scenario and will fail to compile in typical usage.

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