Mandats : origin→FK identité + nomination auto + boutons + tests intégration

- origin TEXT → origin_id UUID FK duniter_identities (migration e3f4a5b6c7d8)
- GET /auth/identities?q= : recherche d'identités par nom/adresse
- MandateCreate.nomination_mode : auto (auto-assign auteur), collective, postpone
- Wizard new.vue : champ origine = picker identité, checkbox "Démarrer maintenant"
- [id].vue : modal "Assigner" = search-picker (résout UUID vs adresse SS58), affiche
  origin_display_name + mandatee_display_name, inputs natifs (<input>/<textarea>)
- Erreurs API visibles dans l'UI (plus de catch silencieux)
- test_mandate_flows.py : 17 tests intégration SQLite réels (origin, nomination,
  assign, lifecycle, revocation, interactions croisées) — 241 tests total OK

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

backend/app/models/mandate.py

@@ -12,10 +12,10 @@ class Mandate(Base):
 
     id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
     title: Mapped[str] = mapped_column(String(256), nullable=False)
-    origin: Mapped[str | None] = mapped_column(Text)           # contexte / déclencheur du mandat
+    origin_id: Mapped[uuid.UUID | None] = mapped_column(ForeignKey("duniter_identities.id"), nullable=True, index=True)
     description: Mapped[str | None] = mapped_column(Text)
-    mandate_type: Mapped[str] = mapped_column(String(64), nullable=False)  # techcomm, smith, custom
-    status: Mapped[str] = mapped_column(String(32), default="draft")  # draft, candidacy, voting, active, reporting, completed, revoked
+    mandate_type: Mapped[str] = mapped_column(String(64), nullable=False)
+    status: Mapped[str] = mapped_column(String(32), default="draft")
     organization_id: Mapped[uuid.UUID | None] = mapped_column(ForeignKey("organizations.id"), nullable=True, index=True)
     mandatee_id: Mapped[uuid.UUID | None] = mapped_column(ForeignKey("duniter_identities.id"))
     decision_id: Mapped[uuid.UUID | None] = mapped_column(ForeignKey("decisions.id"))
@@ -24,7 +24,27 @@ class Mandate(Base):
     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())
 
-    steps: Mapped[list["MandateStep"]] = relationship(back_populates="mandate", cascade="all, delete-orphan", order_by="MandateStep.step_order")
+    steps: Mapped[list["MandateStep"]] = relationship(
+        back_populates="mandate", cascade="all, delete-orphan", order_by="MandateStep.step_order"
+    )
+    origin_identity: Mapped["DuniterIdentity | None"] = relationship(  # type: ignore[name-defined]
+        "DuniterIdentity", foreign_keys=[origin_id]
+    )
+    mandatee: Mapped["DuniterIdentity | None"] = relationship(  # type: ignore[name-defined]
+        "DuniterIdentity", foreign_keys=[mandatee_id]
+    )
+
+    @property
+    def origin_display_name(self) -> str | None:
+        if self.origin_identity is not None:
+            return self.origin_identity.display_name or self.origin_identity.address
+        return None
+
+    @property
+    def mandatee_display_name(self) -> str | None:
+        if self.mandatee is not None:
+            return self.mandatee.display_name or self.mandatee.address
+        return None
 
 
 class MandateStep(Base):
@@ -33,12 +53,16 @@ class MandateStep(Base):
     id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
     mandate_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("mandates.id"), nullable=False)
     step_order: Mapped[int] = mapped_column(Integer, nullable=False)
-    step_type: Mapped[str] = mapped_column(String(32), nullable=False)  # formulation, candidacy, vote, assignment, reporting, completion, revocation
+    step_type: Mapped[str] = mapped_column(String(32), nullable=False)
     title: Mapped[str | None] = mapped_column(String(256))
     description: Mapped[str | None] = mapped_column(Text)
-    status: Mapped[str] = mapped_column(String(32), default="pending")  # pending, active, completed, skipped
+    status: Mapped[str] = mapped_column(String(32), default="pending")
     vote_session_id: Mapped[uuid.UUID | None] = mapped_column(ForeignKey("vote_sessions.id"))
     outcome: Mapped[str | None] = mapped_column(Text)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
 
     mandate: Mapped["Mandate"] = relationship(back_populates="steps")
+
+
+# Avoid circular import — DuniterIdentity imported at runtime by SQLAlchemy relationship resolution
+from app.models.user import DuniterIdentity  # noqa: E402, F401