feat(reasoning): Regulatory Reasoning Engine MVP (scope/obligations/implementation/interpretation)

Deterministic reasoning layer ON TOP of the Legal Knowledge Graph (obligation
registry) and the Compliance Execution Graph (control mapping/evidence). Answers
which regulations apply to a concrete product, which obligations follow, whether
the customer's implementation covers them, and whether a customer interpretation
is too narrow/broad/plausible.

- ProductProfile with tri-state facts (Optional[bool]=None => uncertain, never
  false security); safe predicate evaluator (no eval).
- 6 regulation triggers (CRA/MaschinenVO/RED/EMV/DataAct/NIS2) with missing-fact
  prompts; 24 obligation scope rules.
- CRA obligation_ids RE-USED verbatim from the registry (93 ids) — never re-minted
  (control_uuid trap); Machine/Data-Act flagged proposed=True.
- required_evidence constrained to the framework-agnostic shared evidence catalog;
  capabilities echo the planned Obligation->Capability layer.
- Overlap groups (CRA<->MaschinenVO cyber-safety) + evidence-for-multiple (USP).
- 4 endpoints POST /reasoning/{scope,obligations,implementation-assessment,
  interpretation-assessment}; thin handlers, registered in api/__init__.py.
- 22 tests (5 machine-builder scenarios + 10 acceptance questions). No DB
  migration, no RAG, no new controls.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend-compliance/compliance/reasoning/rules_obligations.py

@@ -0,0 +1,23 @@
+"""Aggregated obligation scope rules + lookup helpers."""
+
+from __future__ import annotations
+
+from typing import Dict, List, Optional
+
+from .rules_obligations_cra import CRA_OBLIGATIONS
+from .rules_obligations_machine_data import DATA_ACT_OBLIGATIONS, MACHINE_OBLIGATIONS
+from .rules_types import ObligationRule
+
+ALL_OBLIGATIONS: List[ObligationRule] = (
+    CRA_OBLIGATIONS + MACHINE_OBLIGATIONS + DATA_ACT_OBLIGATIONS
+)
+
+_BY_ID: Dict[str, ObligationRule] = {o.obligation_id: o for o in ALL_OBLIGATIONS}
+
+
+def obligation_rule(obligation_id: str) -> Optional[ObligationRule]:
+    return _BY_ID.get(obligation_id)
+
+
+def obligations_for_regulation(regulation_id: str) -> List[ObligationRule]:
+    return [o for o in ALL_OBLIGATIONS if o.source_regulation == regulation_id]