Alembic : migration initiale + chaîne idempotente IF NOT EXISTS

- 0b9c1d2e3f4a : migration initiale (CREATE TABLE IF NOT EXISTS) — safe
  sur une DB déjà bootstrappée via create_all()
- 70914b334cfb : ADD COLUMN IF NOT EXISTS (organization_id) — was down_revision=None
- b78571ae9e00 : CREATE TABLE IF NOT EXISTS qualification_protocols
- c4e812fb3a01 : CREATE TABLE IF NOT EXISTS groups + group_members
- d91a3c7f8b02 : ADD COLUMN IF NOT EXISTS origin (mandates)
- Dockerfile prod : restaure alembic upgrade head au démarrage

Sur le serveur prod, exécuter une fois :
  docker exec <projet>-backend alembic upgrade head

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

backend/alembic/versions/2026_04_23_1900-c4e812fb3a01_add_groups.py

@@ -17,31 +17,28 @@ depends_on = None
 
 
 def upgrade() -> None:
-    op.create_table(
-        "groups",
-        sa.Column("id", sa.Uuid(), nullable=False),
-        sa.Column("name", sa.String(128), nullable=False),
-        sa.Column("description", sa.Text(), nullable=True),
-        sa.Column("organization_id", sa.Uuid(), nullable=True),
-        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
-        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
-        sa.ForeignKeyConstraint(["organization_id"], ["organizations.id"]),
-        sa.PrimaryKeyConstraint("id"),
+    op.execute("""
+    CREATE TABLE IF NOT EXISTS groups (
+        id UUID PRIMARY KEY,
+        name VARCHAR(128) NOT NULL,
+        description TEXT,
+        organization_id UUID REFERENCES organizations(id),
+        created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+        updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
     )
-    op.create_index("ix_groups_organization_id", "groups", ["organization_id"])
+    """)
+    op.execute("CREATE INDEX IF NOT EXISTS ix_groups_organization_id ON groups (organization_id)")
 
-    op.create_table(
-        "group_members",
-        sa.Column("id", sa.Uuid(), nullable=False),
-        sa.Column("group_id", sa.Uuid(), nullable=False),
-        sa.Column("identity_id", sa.Uuid(), nullable=True),
-        sa.Column("display_name", sa.String(128), nullable=False),
-        sa.Column("added_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
-        sa.ForeignKeyConstraint(["group_id"], ["groups.id"]),
-        sa.ForeignKeyConstraint(["identity_id"], ["duniter_identities.id"]),
-        sa.PrimaryKeyConstraint("id"),
+    op.execute("""
+    CREATE TABLE IF NOT EXISTS group_members (
+        id UUID PRIMARY KEY,
+        group_id UUID NOT NULL REFERENCES groups(id),
+        identity_id UUID REFERENCES duniter_identities(id),
+        display_name VARCHAR(128) NOT NULL,
+        added_at TIMESTAMPTZ NOT NULL DEFAULT now()
     )
-    op.create_index("ix_group_members_group_id", "group_members", ["group_id"])
+    """)
+    op.execute("CREATE INDEX IF NOT EXISTS ix_group_members_group_id ON group_members (group_id)")
 
 
 def downgrade() -> None: