feat: add allow_custom_bitrate column to instance_settings schema and migration

packages/server/src/db/migrate.ts

@@ -172,6 +172,12 @@ export function runMigrations(db: Database.Database): void {
         { name: 'max_upload_size_bytes', type: 'INTEGER' }
       ]
     },
+    {
+      name: 'instance_settings',
+      columns: [
+        { name: 'allow_custom_bitrate', type: 'INTEGER NOT NULL DEFAULT 1' }
+      ]
+    },
     // gif_api_key is handled by migrateRenameGifApiKey() — do NOT add it here
     // or it will race with the tenor_api_key → gif_api_key rename migration
   ];

packages/server/src/db/schema.ts

@@ -259,6 +259,7 @@ export const instanceSettings = sqliteTable('instance_settings', {
   registrationOpen: integer('registration_open'),  // null = use env var default, 0/1 = explicit
   gifApiKey: text('gif_api_key'),
   bitrateMatrixOverrides: text('bitrate_matrix_overrides'),
+  allowCustomBitrate: integer('allow_custom_bitrate').notNull().default(1),
   maxUploadSizeBytes: integer('max_upload_size_bytes'),
   updatedAt: integer('updated_at').notNull(),
 });