PatternKit has runtime message envelope, headers, and context primitives. Add a source-generated path for strongly typed message contracts and envelope metadata where applications want compile-time declarations.\n\nAcceptance criteria:\n- Add generator attributes for message contracts, standard headers, and envelope metadata.\n- Generate strongly typed helpers with deterministic diagnostics.\n- Include TinyBDD generator/runtime/example coverage.\n- Document fluent/runtime and generated usage side by side.\n- Include IServiceCollection integration for the example surface.\n- Land green on CI, docs, CodeQL, and coverage.
PatternKit has runtime message envelope, headers, and context primitives. Add a source-generated path for strongly typed message contracts and envelope metadata where applications want compile-time declarations.\n\nAcceptance criteria:\n- Add generator attributes for message contracts, standard headers, and envelope metadata.\n- Generate strongly typed helpers with deterministic diagnostics.\n- Include TinyBDD generator/runtime/example coverage.\n- Document fluent/runtime and generated usage side by side.\n- Include IServiceCollection integration for the example surface.\n- Land green on CI, docs, CodeQL, and coverage.