v3 : socle Rust (moteur pur, accès trustinWallet, serveur) ; maquette Nuxt rangée dans maquette/

- crates/ld-engine : formule inertielle (parité avec la maquette, garde C),
  coquille / changement de fond, assistant d'édition à règles, composition
  d'un document sous vote permanent (adoptions, aperçus, rivales).
- crates/trustin-access : qui voit, qui ouvre, qui gère les accès.
- crates/ld-server : API axum + SQLite, connexion Ğ1 (client OAuth2 de
  connect.monnaie-libre.fr), invitations, entrée en vigueur automatique,
  signalements de contradiction, traductions éditoriales, publication git,
  taille de la toile lue sur la chaîne.
- seeds/acte-engagement-certification.json : 33 articles, fr + en + es ;
  en vigueur : préambule, E1, E2 (seed a minima).
- maquette/ : frontend, backend et docker v2 déplacés tels quels.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

maquette/backend/app/models/group.py

@@ -0,0 +1,41 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import String, Text, DateTime, ForeignKey, Uuid, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+class Group(Base):
+    __tablename__ = "groups"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(128), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text)
+    organization_id: Mapped[uuid.UUID | None] = mapped_column(
+        ForeignKey("organizations.id"), nullable=True, index=True
+    )
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), onupdate=func.now()
+    )
+
+    members: Mapped[list["GroupMember"]] = relationship(
+        back_populates="group", cascade="all, delete-orphan"
+    )
+
+
+class GroupMember(Base):
+    __tablename__ = "group_members"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    group_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("groups.id"), nullable=False, index=True)
+    # FK to duniter_identities when the member is a known WoT member; nullable for free-text entries
+    identity_id: Mapped[uuid.UUID | None] = mapped_column(
+        ForeignKey("duniter_identities.id"), nullable=True
+    )
+    display_name: Mapped[str] = mapped_column(String(128), nullable=False)
+    added_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+
+    group: Mapped["Group"] = relationship(back_populates="members")