Spots: a matched spot's NZB isn't kept

Only a spot that becomes a release of its own needs its NZB (the header
pass's releases have their chunks); spots took 2.7 GB on the NVMe at 9k.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

database/migrations/1770000003000_spots_nzb_only_unmatched.ts

@@ -0,0 +1,10 @@
+import { BaseSchema } from '@adonisjs/lucid/schema'
+
+/** A matched spot's NZB isn't kept (its releases have their chunks): only a spot of its own needs one (2.7 GB at 9k spots). */
+export default class extends BaseSchema {
+  async up() {
+    this.schema.raw(`UPDATE spots SET nzb = NULL WHERE matched > 0 AND nzb IS NOT NULL`)
+  }
+
+  async down() {}
+}