refactor(llm-configs):

remove unused reserved_jsonb fields

   Remove the three reserved JSONB fields (reserved_jsonb_1, reserved_jsonb_2, reserved_jsonb_3) from the llm_model_configs
   table. These fields were planned for future use but are no longer needed.

gns3server/db/models/llm_model_configs.py

@@ -42,11 +42,6 @@ class LLMModelConfig(BaseTable):
     is_default = Column(Boolean, default=False, nullable=False)
     version = Column(Integer, default=0, nullable=False)  # Optimistic locking version
 
-    # Reserved fields for future use (currently unused in code)
-    reserved_jsonb_1 = Column(JSON, nullable=True)
-    reserved_jsonb_2 = Column(JSON, nullable=True)
-    reserved_jsonb_3 = Column(JSON, nullable=True)
-
     # Relationships
     user = relationship("User", backref="llm_model_configs")
     group = relationship("UserGroup", backref="llm_model_configs")

gns3server/db_migrations/versions/20260303_create_llm_model_configs_table.py

@@ -42,9 +42,6 @@ def upgrade() -> None:
         sa.Column('version', sa.Integer(), nullable=False, server_default='0'),
         sa.Column('created_at', sa.DateTime(), nullable=True),
         sa.Column('updated_at', sa.DateTime(), nullable=True),
-        sa.Column('reserved_jsonb_1', sa.JSON(), nullable=True, comment='Reserved field for future use'),
-        sa.Column('reserved_jsonb_2', sa.JSON(), nullable=True, comment='Reserved field for future use'),
-        sa.Column('reserved_jsonb_3', sa.JSON(), nullable=True, comment='Reserved field for future use'),
         sa.CheckConstraint(
             "(user_id IS NOT NULL AND group_id IS NULL) OR "
             "(user_id IS NULL AND group_id IS NOT NULL)",