Declare TypeKit's tested platforms with MetalamaPlatformRequirement #224

Goal

Have the Generators package declare the platforms it is tested on, so a consumer outside them gets a build warning instead of an untested weave. Needs #173.

Metalama 2027.0 warns when the target framework, the .NET SDK or the Visual Studio version is outside the matrix Metalama tests (LAMA0600 onwards, one code per dimension). A package built on Metalama can declare stricter requirements with the MetalamaPlatformRequirement MSBuild item, reported by the same check (release notes, "Warnings for untested configurations").

What to declare

TypeKit's tested matrix is net10.0 and net11.0, the SDK bands CI runs, and the IDE hosts that #173's weaving review checks. The README already names the minimum IDE versions, since an unsupported host fails silently. Each requirement must match a lane that actually runs; no requirement for what isn't tested.

Done when

• The requirement ships in the Generators package's build assets.
• The smoke test shows a consumer outside it getting the warning, and one inside it getting none.
• The Generators README and the changelog name it, with how to suppress one dimension (NoWarn) or the check (MetalamaCheckSupportedPlatform).