Restructure Engagement Forgeron + fix GenesisBlock + InertiaSlider

- Seed: restructure Engagement Forgeron (51→59 items) avec 3 nouvelles
  sections: Engagements fondamentaux (EF1-EF3), Engagements techniques
  (ET1-ET3), Qualification (Q0-Q1) liée au protocole Embarquement
- Seed: ajout protocole Embarquement Forgeron (5 jalons: candidature,
  miroir, évaluation, certification Smith, mise en ligne)
- GenesisBlock: fix lisibilité — fond mood-surface teinté accent au lieu
  de mood-text inversé, texte mood-aware au lieu de rgba blanc hardcodé
- InertiaSlider: mini affiche "Inertie" sous le curseur, compact en
  width:fit-content pour s'adapter au label
- Frontend: ajout section qualification dans SECTION_META/SECTION_ORDER
- Pages, composants et tests des sprints précédents

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/tests/test_public_api.py

@@ -43,6 +43,7 @@ def _make_document_mock(
     doc.description = description
     doc.ipfs_cid = None
     doc.chain_anchor = None
+    doc.genesis_json = None
     doc.created_at = datetime.now(timezone.utc)
     doc.updated_at = datetime.now(timezone.utc)
     doc.items = []
@@ -68,6 +69,9 @@ def _make_item_mock(
     item.current_text = current_text
     item.voting_protocol_id = None
     item.sort_order = sort_order
+    item.section_tag = None
+    item.inertia_preset = "standard"
+    item.is_permanent_vote = True
     item.created_at = datetime.now(timezone.utc)
     item.updated_at = datetime.now(timezone.utc)
     return item
@@ -135,8 +139,8 @@ class TestDocumentOutSchema:
 
         expected_fields = {
             "id", "slug", "title", "doc_type", "version", "status",
-            "description", "ipfs_cid", "chain_anchor", "created_at",
-            "updated_at", "items_count",
+            "description", "ipfs_cid", "chain_anchor", "genesis_json",
+            "created_at", "updated_at", "items_count",
         }
         assert expected_fields.issubset(set(data.keys()))