fix(epg): address second round of reviewer feedback

- Fix NameError in sd_lineups_search: add dispatcharr_version import
- Fix DELETE handler: persist changesRemaining from SD response to custom_properties
- Fix lockout reset time: calculate next midnight UTC (00:00Z) instead of
  rolling now+24h, matching SD's documented reset behavior
- Remove redundant explicit index from SDProgramMD5: unique_together already
  creates this index in Postgres
- Regenerate 0023_schedules_direct migration to incorporate all changes cleanly
  in a single migration

apps/epg/migrations/0023_schedules_direct.py

@@ -1,4 +1,4 @@
-# Generated by Django 6.0.4 on 2026-05-18 22:38
+# Generated by Django 6.0.4 on 2026-05-19 23:55
 
 import django.db.models.deletion
 from django.db import migrations, models
@@ -39,7 +39,6 @@ class Migration(migrations.Migration):
                 ('epg_source', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='sd_program_md5s', to='epg.epgsource')),
             ],
             options={
-                'indexes': [models.Index(fields=['epg_source', 'program_id'], name='epg_sdprogr_epg_sou_222ce1_idx')],
                 'unique_together': {('epg_source', 'program_id')},
             },
         ),

apps/epg/migrations/0024_remove_sdprogrammd5_redundant_index.py

@@ -1,17 +0,0 @@
-# Generated by Django 6.0.4 on 2026-05-19 23:46
-
-from django.db import migrations
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('epg', '0023_schedules_direct'),
-    ]
-
-    operations = [
-        migrations.RemoveIndex(
-            model_name='sdprogrammd5',
-            name='epg_sdprogr_epg_sou_222ce1_idx',
-        ),
-    ]