feat: add alembic migration for LLMConfig privileges

Add migration to insert LLMConfig.Audit, LLMConfig.Modify, LLMConfig.Allocate
privileges into existing databases and associate LLMConfig.Audit/Modify
with the default User role.

gns3server/db_migrations/versions/a8829e6c069b_add_llm_config_privileges.py

@@ -0,0 +1,113 @@
+"""add llm config privileges to existing database
+
+Revision ID: a8829e6c069b
+Revises: aff810fc119a
+Create Date: 2026-05-26
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from uuid import uuid4
+
+# revision identifiers, used by Alembic.
+revision = 'a8829e6c069b'
+down_revision = 'aff810fc119a'
+branch_labels = None
+depends_on = None
+
+privileges_table = sa.table(
+    'privileges',
+    sa.column('privilege_id', sa.String),
+    sa.column('name', sa.String),
+    sa.column('description', sa.String),
+)
+
+roles_table = sa.table(
+    'roles',
+    sa.column('role_id', sa.String),
+    sa.column('name', sa.String),
+)
+
+privilege_role_map = sa.table(
+    'privilege_role_map',
+    sa.column('privilege_id', sa.String),
+    sa.column('role_id', sa.String),
+)
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+
+    # Insert new LLMConfig privileges if they don't already exist
+    new_privileges = [
+        {"name": "LLMConfig.Allocate", "description": "Create or delete an LLM model configuration"},
+        {"name": "LLMConfig.Audit", "description": "View an LLM model configuration"},
+        {"name": "LLMConfig.Modify", "description": "Update an LLM model configuration"},
+    ]
+
+    privilege_ids = {}
+    for priv in new_privileges:
+        result = conn.execute(
+            sa.select(privileges_table.c.privilege_id).where(
+                privileges_table.c.name == priv["name"]
+            )
+        ).fetchone()
+
+        if result:
+            privilege_ids[priv["name"]] = result[0]
+        else:
+            priv_id = str(uuid4())
+            conn.execute(
+                privileges_table.insert().values(
+                    privilege_id=priv_id,
+                    name=priv["name"],
+                    description=priv["description"],
+                )
+            )
+            privilege_ids[priv["name"]] = priv_id
+
+    # Add LLMConfig.Audit and LLMConfig.Modify to the User role
+    user_role = conn.execute(
+        sa.select(roles_table.c.role_id).where(roles_table.c.name == "User")
+    ).fetchone()
+
+    if user_role:
+        user_role_id = user_role[0]
+        for priv_name in ("LLMConfig.Audit", "LLMConfig.Modify"):
+            conn.execute(
+                privilege_role_map.insert().values(
+                    privilege_id=privilege_ids[priv_name],
+                    role_id=user_role_id,
+                )
+            )
+
+
+def downgrade() -> None:
+    conn = op.get_bind()
+
+    user_role = conn.execute(
+        sa.select(roles_table.c.role_id).where(roles_table.c.name == "User")
+    ).fetchone()
+
+    if user_role:
+        user_role_id = user_role[0]
+        for priv_name in ("LLMConfig.Audit", "LLMConfig.Modify"):
+            priv = conn.execute(
+                sa.select(privileges_table.c.privilege_id).where(
+                    privileges_table.c.name == priv_name
+                )
+            ).fetchone()
+            if priv:
+                conn.execute(
+                    privilege_role_map.delete().where(
+                        privilege_role_map.c.privilege_id == priv[0],
+                        privilege_role_map.c.role_id == user_role_id,
+                    )
+                )
+
+    for priv_name in ("LLMConfig.Allocate", "LLMConfig.Audit", "LLMConfig.Modify"):
+        conn.execute(
+            privileges_table.delete().where(
+                privileges_table.c.name == priv_name
+            )
+        )