feat: enhance agent management with session handling and UI improvements

backend/alembic/versions/d3e4f5a6b7c8_add_agent_token_hash.py

@@ -0,0 +1,38 @@
+"""add agent token hash
+
+Revision ID: d3e4f5a6b7c8
+Revises: c7f0a2b1d4e3
+Create Date: 2026-02-04 06:50:00.000000
+
+"""
+
+from __future__ import annotations
+
+from alembic import op
+import sqlalchemy as sa
+import sqlmodel
+
+
+# revision identifiers, used by Alembic.
+revision = "d3e4f5a6b7c8"
+down_revision = "c7f0a2b1d4e3"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "agents",
+        sa.Column("agent_token_hash", sqlmodel.sql.sqltypes.AutoString(), nullable=True),
+    )
+    op.create_index(
+        op.f("ix_agents_agent_token_hash"),
+        "agents",
+        ["agent_token_hash"],
+        unique=False,
+    )
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_agents_agent_token_hash"), table_name="agents")
+    op.drop_column("agents", "agent_token_hash")