feat(completeness): Regulatory Completeness Engine — auditable coverage, not confidence

Phase A½. The move from feature to product development: for every assessment, answer "how sure are
we that this answer is COMPLETE?" — different from confidence. The product never claims full coverage;
it makes its own knowledge state transparent and auditable. Shows what we do NOT know and why.

- compliance/completeness/: assess_completeness(identified, corpus_status, uncertain, assumptions,
  assessed_obligations) -> CompletenessReport. Separates IDENTIFIED from ASSESSED (validated corpus
  AND determined applicability) and justifies every gap. Two kinds of open: corpus gap (future_corpus)
  and applicability uncertainty (query_required + deciding question, e.g. Data Act / generates_usage_data).
- The metric is COUNTS, never a single percentage: "Identifiziert N · bewertet M · offen K ·
  Unsicherheiten U · Begründung ja" + an honest audit statement.
- ADR-007: auditable honesty; phase order A factory -> A½ Completeness -> B new domains; the
  transparency selling point. Deterministic, no LLM; corpus status + obligation count injected.
- reference suite: "Regulatory Completeness" section runs an industrial-dishwasher assessment
  (assessed CRA/MaschinenVO; open EMV/Environmental=future_corpus, Data Act=query_required) and notes
  Environmental flips open->validated automatically once the corpus lands.

11 completeness tests (54 with adjacent modules), mypy --strict clean (15 files), check-loc 0.
Product code with no app caller + ADR/reference = non-runtime -> no deploy (ADR-001). Freeze-safe.

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

backend-compliance/reference_scenarios/generate.py

@@ -46,7 +46,7 @@ import yaml
 
 from _helpers import (  # noqa: E402  (script-dir module; keeps generate.py under the LOC budget)
     OUT, ROLLUP, Row, w, coverage_table, reg_map_block, unsupported_block, interp_status,
-    knowledge_intake_section,
+    knowledge_intake_section, completeness_section,
 )
 
 ISO_MAP = {"ISO27001": CapabilityMappingEntry(
@@ -465,6 +465,7 @@ coverage_table([
 ])
 
 knowledge_intake_section(os.path.dirname(__file__))   # Knowledge Intake (impact triage) — kept in _helpers for LOC
+completeness_section()                                 # Regulatory Completeness — kept in _helpers for LOC
 
 # ── Epics + roll-up ───────────────────────────────────────────────────────
 w("## Gaps → Epics (Backlog — nur erfasst, NICHT implementiert)")