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/routers/decisions.py

@@ -13,13 +13,16 @@ from app.database import get_db
 from app.models.decision import Decision, DecisionStep
 from app.models.user import DuniterIdentity
 from app.schemas.decision import (
+    DecisionAdvanceOut,
     DecisionCreate,
     DecisionOut,
     DecisionStepCreate,
     DecisionStepOut,
     DecisionUpdate,
 )
+from app.schemas.vote import VoteSessionOut
 from app.services.auth_service import get_current_identity
+from app.services.decision_service import advance_decision, create_vote_session_for_step
 
 router = APIRouter()
 
@@ -141,3 +144,64 @@ async def add_step(
     await db.refresh(step)
 
     return DecisionStepOut.model_validate(step)
+
+
+# ── Workflow routes ────────────────────────────────────────────────────────
+
+
+@router.post("/{id}/advance", response_model=DecisionAdvanceOut)
+async def advance_decision_endpoint(
+    id: uuid.UUID,
+    db: AsyncSession = Depends(get_db),
+    identity: DuniterIdentity = Depends(get_current_identity),
+) -> DecisionAdvanceOut:
+    """Advance a decision to its next step or status."""
+    try:
+        decision = await advance_decision(id, db)
+    except ValueError as exc:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc))
+
+    # Reload with steps for complete output
+    decision = await _get_decision(db, decision.id)
+    data = DecisionOut.model_validate(decision).model_dump()
+    data["message"] = f"Decision avancee au statut : {decision.status}"
+    return DecisionAdvanceOut(**data)
+
+
+@router.post(
+    "/{id}/steps/{step_id}/create-vote-session",
+    response_model=VoteSessionOut,
+    status_code=status.HTTP_201_CREATED,
+)
+async def create_vote_session_for_step_endpoint(
+    id: uuid.UUID,
+    step_id: uuid.UUID,
+    db: AsyncSession = Depends(get_db),
+    identity: DuniterIdentity = Depends(get_current_identity),
+) -> VoteSessionOut:
+    """Create a vote session linked to a decision step."""
+    try:
+        session = await create_vote_session_for_step(id, step_id, db)
+    except ValueError as exc:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc))
+
+    return VoteSessionOut.model_validate(session)
+
+
+@router.delete("/{id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_decision(
+    id: uuid.UUID,
+    db: AsyncSession = Depends(get_db),
+    identity: DuniterIdentity = Depends(get_current_identity),
+) -> None:
+    """Delete a decision (only if in draft status)."""
+    decision = await _get_decision(db, id)
+
+    if decision.status != "draft":
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Seules les decisions en brouillon peuvent etre supprimees",
+        )
+
+    await db.delete(decision)
+    await db.commit()