feat: add PPAC candidate tab and status

backend/migrations/versions/0022_ppac_candidate.py

@@ -0,0 +1,41 @@
+"""Classify snapshots whose sole Alpha failure is the unopened PPAC theme."""
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = "0022"
+down_revision = "0021"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Reuse the indexed check_type column; preserve all raw evidence and check stages.
+    table = sa.table("alphas", sa.column("id", sa.String()), sa.column("checks", sa.JSON()),
+                     sa.column("check_type", sa.String(20)))
+    connection = op.get_bind()
+    last_id = None
+    while True:
+        query = sa.select(table.c.id, table.c.checks).order_by(table.c.id).limit(500)
+        if last_id is not None:
+            query = query.where(table.c.id > last_id)
+        rows = connection.execute(query).mappings().all()
+        if not rows:
+            break
+        candidates = []
+        for row in rows:
+            # Freeze the current interpretation instead of importing application code.
+            checks = row["checks"] if isinstance(row["checks"], list) else []
+            failures = [check for check in checks if isinstance(check, dict)
+                        and check.get("name") != "REGULAR_SUBMISSION"
+                        and isinstance(check.get("result"), str) and check["result"].upper() == "FAIL"]
+            if len(failures) == 1 and failures[0].get("name") == "PURE_POWER_POOL_THEME":
+                candidates.append(row["id"])
+        if candidates:
+            connection.execute(table.update().where(table.c.id.in_(candidates)).values(check_type="PPAC_CANDIDATE"))
+        last_id = rows[-1]["id"]
+
+
+def downgrade():
+    table = sa.table("alphas", sa.column("check_type", sa.String(20)))
+    op.execute(table.update().where(table.c.check_type == "PPAC_CANDIDATE").values(check_type="FAIL_1"))