Annotation Removal

Current posture: YAML authority is rising, but annotations remain part of extraction.

Annotation	Current role	Portability stance
@PipelineStep	Build-time marker and metadata source	Make optional; migrate metadata to YAML or neutral descriptors
@PipelineOrchestrator	Orchestrator endpoint and generation trigger	Replace with YAML orchestrator declaration
@PipelinePlugin	Plugin host marker	Replace with service descriptor metadata
@GeneratedRole	Internal generated marker	Keep internally
@ParallelismHint	Runtime/compiler hint	Keep as neutral internal metadata or descriptor fields

Suggested migration path:

1. Keep annotations supported.
2. Make YAML service declarations authoritative.
3. Validate service signatures directly from YAML class names.
4. Warn on annotation/YAML conflicts.
5. Move operational metadata (cache keys, ordering, virtual thread hints, side-effects) to YAML.
6. End with annotations optional, then remove Quarkus-only public annotation coupling.