Groupes d'identités : modèle DB, router, store, UI cercles + Protocoles

- Group + GroupMember : modèle SQLAlchemy + migration + router CRUD
- /api/v1/groups : liste, création, suppression, membres (add/remove)
- groups.ts : store Pinia (fetchAll, getGroup, create, remove, addMember, removeMember)
- decisions/new.vue : cercles 1 & 2 en mode texte libre OU groupe prédéfini
  (affected_count calculé depuis le member_count du groupe)
- protocols/index.vue : section Groupes avec expand/collapse, ajout/suppression membres
- lang="fr" + spellcheck sur tous les textareas ; placeholder cercle 2 corrigé
- n8n channels : prévu sprint futur (texte libre → webhook appel à contribution)

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

backend/app/routers/groups.py

@@ -0,0 +1,126 @@
+"""Groups router — predefined sets of Duniter identities used in decision circles."""
+
+from __future__ import annotations
+
+import uuid
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.responses import Response
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import selectinload
+
+from app.database import get_db
+from app.models.group import Group, GroupMember
+from app.schemas.group import GroupCreate, GroupMemberCreate, GroupMemberOut, GroupOut, GroupSummary
+from app.services.auth_service import get_current_identity
+
+router = APIRouter()
+
+
+def _org_id_from_header(request_headers) -> uuid.UUID | None:
+    raw = request_headers.get("x-organization")
+    if not raw:
+        return None
+    try:
+        return uuid.UUID(raw)
+    except ValueError:
+        return None
+
+
+@router.get("/", response_model=list[GroupSummary])
+async def list_groups(
+    db: AsyncSession = Depends(get_db),
+) -> list[GroupSummary]:
+    """List all groups. No auth required — groups are public within the workspace."""
+    result = await db.execute(
+        select(Group).options(selectinload(Group.members)).order_by(Group.name)
+    )
+    groups = result.scalars().all()
+    return [
+        GroupSummary(
+            id=g.id,
+            name=g.name,
+            description=g.description,
+            organization_id=g.organization_id,
+            member_count=len(g.members),
+        )
+        for g in groups
+    ]
+
+
+@router.post("/", response_model=GroupOut, status_code=201)
+async def create_group(
+    payload: GroupCreate,
+    db: AsyncSession = Depends(get_db),
+    _identity=Depends(get_current_identity),
+) -> GroupOut:
+    group = Group(name=payload.name, description=payload.description)
+    db.add(group)
+    await db.commit()
+    await db.refresh(group)
+    await db.execute(select(Group).where(Group.id == group.id).options(selectinload(Group.members)))
+    return GroupOut.model_validate(group)
+
+
+@router.get("/{group_id}", response_model=GroupOut)
+async def get_group(group_id: uuid.UUID, db: AsyncSession = Depends(get_db)) -> GroupOut:
+    result = await db.execute(
+        select(Group).where(Group.id == group_id).options(selectinload(Group.members))
+    )
+    group = result.scalar_one_or_none()
+    if group is None:
+        raise HTTPException(status_code=404, detail="Group not found")
+    return GroupOut.model_validate(group)
+
+
+@router.delete("/{group_id}", status_code=204, response_class=Response, response_model=None)
+async def delete_group(
+    group_id: uuid.UUID,
+    db: AsyncSession = Depends(get_db),
+    _identity=Depends(get_current_identity),
+) -> None:
+    result = await db.execute(select(Group).where(Group.id == group_id))
+    group = result.scalar_one_or_none()
+    if group is None:
+        raise HTTPException(status_code=404, detail="Group not found")
+    await db.delete(group)
+    await db.commit()
+
+
+@router.post("/{group_id}/members", response_model=GroupMemberOut, status_code=201)
+async def add_member(
+    group_id: uuid.UUID,
+    payload: GroupMemberCreate,
+    db: AsyncSession = Depends(get_db),
+    _identity=Depends(get_current_identity),
+) -> GroupMemberOut:
+    result = await db.execute(select(Group).where(Group.id == group_id))
+    if result.scalar_one_or_none() is None:
+        raise HTTPException(status_code=404, detail="Group not found")
+    member = GroupMember(
+        group_id=group_id,
+        display_name=payload.display_name,
+        identity_id=payload.identity_id,
+    )
+    db.add(member)
+    await db.commit()
+    await db.refresh(member)
+    return GroupMemberOut.model_validate(member)
+
+
+@router.delete("/{group_id}/members/{member_id}", status_code=204, response_class=Response, response_model=None)
+async def remove_member(
+    group_id: uuid.UUID,
+    member_id: uuid.UUID,
+    db: AsyncSession = Depends(get_db),
+    _identity=Depends(get_current_identity),
+) -> None:
+    result = await db.execute(
+        select(GroupMember).where(GroupMember.id == member_id, GroupMember.group_id == group_id)
+    )
+    member = result.scalar_one_or_none()
+    if member is None:
+        raise HTTPException(status_code=404, detail="Member not found")
+    await db.delete(member)
+    await db.commit()