Sprint 4 : decisions et mandats -- workflow complet + vote integration

Backend: 7 nouveaux endpoints (advance, assign, revoke, create-vote-session),
services enrichis avec creation de sessions de vote, assignation de mandataire
et revocation. 35 nouveaux tests (104 total). Frontend: store mandates, page
cadrage decisions, detail mandats, composants DecisionWorkflow, DecisionCadrage,
DecisionCard, MandateTimeline, MandateCard. Documentation mise a jour.

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

backend/app/schemas/decision.py

@@ -70,3 +70,22 @@ class DecisionOut(BaseModel):
     created_at: datetime
     updated_at: datetime
     steps: list[DecisionStepOut] = Field(default_factory=list)
+
+
+class DecisionAdvanceOut(BaseModel):
+    """Output after advancing a decision through its workflow."""
+
+    model_config = ConfigDict(from_attributes=True)
+
+    id: UUID
+    title: str
+    description: str | None = None
+    context: str | None = None
+    decision_type: str
+    status: str
+    voting_protocol_id: UUID | None = None
+    created_by_id: UUID | None = None
+    created_at: datetime
+    updated_at: datetime
+    steps: list[DecisionStepOut] = Field(default_factory=list)
+    message: str = Field(..., description="Message decrivant l'avancement effectue")