fix(workspace/db): repair channels stuck at alembic 025 (missing orchestration columns)

workspace/backend/alembic/versions/026_ensure_channel_orchestration.py

@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+"""Ensure channel orchestration columns exist (repair for stuck revision 025).
+
+Revision ID: 026
+Revises: 025
+Create Date: 2026-07-09
+
+Background
+----------
+Two divergent migrations were both authored as revision "025":
+
+  - ``025_add_channel_orchestration`` (this lineage / origin/develop /
+    release) adds ``channels.orchestration_mode`` and
+    ``channels.orchestration_instruction``.
+  - ``025_add_evaluation_jobs`` (an experimental SWE-bench lineage) creates
+    the ``evaluation_jobs`` table.
+
+Because both declared ``revision = "025"``, any database that ran the
+evaluation-jobs variant first got stamped ``alembic_version = '025'``. When
+the orchestration code later deployed, ``alembic upgrade head`` saw the DB
+already at "025" and became a no-op — so the orchestration columns were
+never created. Every channel-list / ``/v1/discover`` query then 500s with
+``column channels.orchestration_mode does not exist``.
+
+This migration re-applies the orchestration columns idempotently so a
+database stuck at "025" (missing the columns) is repaired on the next
+deploy, while a database that already has them is left untouched. Uses
+Postgres ``ADD COLUMN IF NOT EXISTS`` for true idempotency.
+"""
+
+from alembic import op
+
+
+revision = "026"
+down_revision = "025"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Idempotent: repairs DBs stuck at "025" without the columns, and is a
+    # no-op where 025_add_channel_orchestration already applied them.
+    op.execute(
+        "ALTER TABLE channels "
+        "ADD COLUMN IF NOT EXISTS orchestration_mode TEXT NOT NULL DEFAULT 'dynamic'"
+    )
+    op.execute(
+        "ALTER TABLE channels "
+        "ADD COLUMN IF NOT EXISTS orchestration_instruction TEXT"
+    )
+
+
+def downgrade() -> None:
+    # No-op: leave the columns in place. 025's downgrade owns dropping them,
+    # and dropping here would fight that revision on a normal downgrade path.
+    pass