feat(rci): Regulatory Change Intelligence foundation (delta over the stored map)

RCI/Delta as a read-/reasoning layer ON TOP of the product-first pipeline. Answers
"what changes relative to my existing Regulatory Map?" — NOT "what does the new
law say in general". No UI, no ingestion (newsletter/mailbox), no RAG, no new
regulations/controls, no legal evaluation outside the stored map.

- 4 core objects (compliance/rci/schemas.py): ComplianceBaseline (snapshot of
  profile + map + registry obligations + required/present evidence), RegulatoryChange
  (simulated/provided INPUT), ObligationDelta (delta_type NEW|CHANGED|REMOVED|
  ALREADY_COVERED|NEEDS_REVIEW|NOT_APPLICABLE), ChangeImpactSummary. delta_type is a
  THIRD vocabulary, disjoint from ClaimCoverage (Welt 1) and ComplianceStatus (Welt 2).
- create_baseline() snapshots the existing pipeline once; assess_change() computes
  deltas deterministically against the snapshot (no re-evaluation).
- 12 tests = the 5 acceptance questions (affects product? new/changed? already
  covered by evidence? needs human review? not relevant?) + repeal/uncertain-reg/
  missing-evidence/boundary. Existing pipeline tests stay green; mypy clean; LOC ok.
- App/reasoning types only — no compliance-meta-model classes (freeze v1.0 untouched).

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

backend-compliance/compliance/rci/__init__.py

@@ -0,0 +1,34 @@
+"""Regulatory Change Intelligence (RCI) — delta layer over the product-first map.
+
+Answers "what changes relative to my existing Regulatory Map?" — NOT "what does
+the new law say in general". Snapshot the pipeline into a ComplianceBaseline, then
+assess a (simulated/provided) RegulatoryChange into per-obligation deltas + a
+management ChangeImpactSummary. Read/reasoning only — no UI, no ingestion, no RAG,
+no new regulations/controls, no legal evaluation outside the stored map.
+"""
+
+from __future__ import annotations
+
+from .baseline import create_baseline
+from .delta_engine import assess_change
+from .schemas import (
+    ChangeAssessment,
+    ChangeImpactSummary,
+    ChangeType,
+    ComplianceBaseline,
+    DeltaType,
+    ObligationDelta,
+    RegulatoryChange,
+)
+
+__all__ = [
+    "create_baseline",
+    "assess_change",
+    "ComplianceBaseline",
+    "RegulatoryChange",
+    "ObligationDelta",
+    "ChangeImpactSummary",
+    "ChangeAssessment",
+    "DeltaType",
+    "ChangeType",
+]