fix(migrations): dropping the demo also takes its reset job's interval-change audit rows

0098 deleted the reset job's run rows but not the scheduler_interval rows that changing its interval
wrote; with the job's label gone they rendered as a raw id. The delete now takes every job-targeted
row for it, and a test seeds both kinds below 0098 and upgrades (red on the old filter). The test
has its own file so the removed-features guard can name it.

backend/alembic/versions/0098_drop_demo_account.py

@@ -5,9 +5,9 @@ schedule — goes with its code. Prod held the demo user and 10 whitelist rows.
 
 The upgrade deletes the demo user first (its playlists, states and subscriptions cascade; audit and
 quota rows keep their history with the actor nulled, as for any deleted account), then the traces
-that only the demo code could render: its audit rows (whitelist edits, manual resets, the scheduled
+that only the demo code could render: its audit rows (whitelist edits, manual resets, and every row
-reset's job runs), the reset job's interval override and its completion notices. Nothing is
+about the reset job — its runs and its interval changes), the reset job's interval override and its
-migrated anywhere; the nightly backup holds the rows.
+completion notices. Nothing is migrated anywhere; the nightly backup holds the rows.
 
 The downgrade restores the schema as it stood (0014), empty: the demo user is created lazily on its
 first sign-in, so an empty `demo_whitelist` is the whole of its state.
@@ -26,7 +26,7 @@ def upgrade() -> None:
     op.execute("DELETE FROM users WHERE is_demo")
     op.execute(
         "DELETE FROM audit_log WHERE action IN ('demo_add', 'demo_remove', 'demo_reset')"
-        " OR (action = 'job_run' AND target_id = 'demo_reset')"
+        " OR (target_type = 'job' AND target_id = 'demo_reset')"
     )
     op.execute("DELETE FROM scheduler_settings WHERE job_id = 'demo_reset'")
     op.execute("DELETE FROM notifications WHERE data->>'job_id' = 'demo_reset'")

backend/tests/test_migration_0098.py

@@ -0,0 +1,35 @@
+"""Migration 0098's data cleanup, DB-lane.
+
+The schema half of every migration is checked by test_migrations.py; this one also deletes rows, and
+a delete that misses a row is invisible there. Its own file so the removed-features guard can name it.
+"""
+
+from alembic import command
+from alembic.config import Config
+from sqlalchemy import text
+
+from app.db import engine
+
+
+def test_dropping_the_demo_takes_every_audit_row_about_its_reset_job(db):
+    # The reset job's interval could be changed from the scheduler page like any job's; once its
+    # name is gone from the UI, a left-behind row would render as a raw job id.
+    cfg = Config("alembic.ini")
+    command.downgrade(cfg, "0097_drop_messages")
+    try:
+        with engine.begin() as conn:
+            conn.execute(
+                text(
+                    "INSERT INTO audit_log (action, target_type, target_id, created_at) VALUES"
+                    " ('job_run', 'job', 'demo_reset', now()),"
+                    " ('scheduler_interval', 'job', 'demo_reset', now()),"
+                    " ('scheduler_interval', 'job', 'sync_feed', now())"
+                )
+            )
+    finally:
+        command.upgrade(cfg, "head")
+    with engine.connect() as conn:
+        left = conn.execute(
+            text("SELECT action, target_id FROM audit_log WHERE target_type = 'job' ORDER BY id")
+        ).all()
+    assert [tuple(r) for r in left] == [("scheduler_interval", "sync_feed")]

frontend/src/lib/removedFeatures.contract.test.ts

@@ -9,7 +9,8 @@ import { describe, expect, it } from "vitest";
 //
 // Not scanned: the Alembic migrations (0014 added the account and 0098 removed it, and both stay true
 // as history) and the release notes, which record what shipped when. `audit_metrics.py` counts the
-// footprint by this same word, so it names it on purpose.
+// footprint by this same word, and test_migration_0098.py tests the removal itself, so both name it
+// on purpose.
 
 const REPO = new URL("../../../", import.meta.url);
 const ROOTS = ["backend/app", "backend/tests", "frontend/src", "frontend/e2e", "scripts"];
@@ -18,6 +19,7 @@ const EXTENSIONS = /\.(py|ts|tsx|js|mjs|json|css|md|sh)$/;
 const ALLOWED = new Set([
   "frontend/src/lib/removedFeatures.contract.test.ts",
   "scripts/audit_metrics.py",
+  "backend/tests/test_migration_0098.py",
 ]);
 // "demo" as a word or an identifier part (`is_demo`, `DemoBanner`, `tryDemo`) — not "demote" (a role
 // change) and not "Demokratikus" (a country's Hungarian name in the vocab).