fix(onboarding): apply hypothesis/vocabulary review decisions (ISO13485, patch-policy rationale, summary)

Two reviewed knowledge decisions (2026-06-28) + the deferred cosmetic counter, before #59.

1. ISO13485 removed from the incident_management hypothesis. ISO 13485 CAPA / quality-safety incident
   handling is NOT security incident management — the mapping was too broad and would seed false
   hypotheses for the empirical loop. A dedicated manage_quality_and_safety_incidents capability can come
   later IF a target needs it; not forced now. (ISO27001/TISAX/IEC62443 keep incident_management.)

2. patch_policy_doc -> secure_signed_update_distribution stays `partial`, but the curated rationale is
   sharpened: "indicates update governance, does not evidence signed distribution" (a patch policy is not
   proof of SIGNED distribution). New optional SignalMapping.rationale field carries the curated note.
   (github_actions_ci -> SDL and dependency_scanning -> vuln-mgmt reviewed and APPROVED as-is.)

3. Cosmetic (folded in since we touched the file): the silent-intake summary now counts detected and
   indications SEPARATELY ("N automatisch erkannt, M Indikation(en)") instead of lumping partial signals
   into "automatisch erkannt" — consistent with the three-state model just shipped.

Tests: ISO13485 no longer resolves to incident_management; summary counts split correctly. 29 onboarding
tests pass, mypy --strict clean, demo runs, check-loc 0. Runtime-visible (hypothesis resolution + summary
text) -> deploy + smoke.

backend-compliance/tests/test_silent_intake.py

@@ -85,6 +85,8 @@ def test_partial_signal_is_indicative_not_detected():
     res = silent_intake([IntakeSignal(source="repository", signal="github_actions_ci")], _MAP)
     assert "secure_development_lifecycle" not in res.capability_ids()           # not counted as present
     assert res.indicative_capability_ids() == ["secure_development_lifecycle"]  # surfaced as an indication
+    # the summary counts detected and indications SEPARATELY (no over-claim of "automatisch erkannt")
+    assert "0 Fähigkeit(en) automatisch erkannt, 1 Indikation(en)" in res.summary
 
 
 def test_partial_indication_does_not_remove_the_question():