Per #114 sub-PR 2/4. Pydantic v2 models + CRUD service. 14 passing tests. API: list/get/get_default/create/update/delete_profile + resolve_weights fallback to system defaults. Validation: ALLOWED_CATEGORIES guard + weight bounds [-2.0, 3.0]. Default-uniqueness в одной transaction (job_settings.py pattern). Vault: code/modules/Module_Weight_Profiles_Service.md. Refs: #114 Co-authored-by: lekss361 <claudestars@proton.me>
