fix: repair SQL_ASCII signature encoding

api/prisma/migrations/20260722190000_repair_sql_ascii_signature_utf8/migration.sql

@@ -0,0 +1,19 @@
+-- The previous bracket-normalization migration ran against a legacy SQL_ASCII
+-- database. PostgreSQL treated the UTF-8 bracket regexp as individual bytes and
+-- removed the trailing 0x91 byte from the final Chinese character in two known
+-- signatures. Restore only the rows whose primary key and corrupt byte sequence
+-- both match the pre-migration backup, so later user edits cannot be overwritten.
+UPDATE "SmsSignature"
+SET name = convert_from(
+  decode('e38090e888aae5a4a9e4bfa1e681afe4bfa1e8afbae7bd91e38091', 'hex'),
+  'SQL_ASCII'
+)
+WHERE id IN (
+  'cmrj2ci1r00544pnkt64wza4e',
+  'cmrobgqp7002nwenke5wh09fr'
+)
+AND encode(convert_to(name, 'SQL_ASCII'), 'hex') =
+  'e38090e888aae5a4a9e4bfa1e681afe4bfa1e8afbae7bde38091';
+
+-- Rollback guidance: do not restore the invalid byte sequence. If rollback is
+-- required, keep the repaired UTF-8 values and only roll back application code.