refactor(bootstrap): migrate payment items to seed file

Lifts ImportPaymentItems out of GlobalsImporter into a dedicated
PaymentItemImporter driven by Data/seeds/payment-items.json. Wired
into Program.cs and SVSimTestFactory.SeedGlobalsAsync after
PracticeOpponentImporter. Drops the prod-capture file in favor of
the extractor pipeline.

Canonical 4-test suite (basic, idempotent, leave-untouched, skip-zero)
keeps the dict-in-sync upsert pattern Task 2 established.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.UnitTests/Infrastructure/SVSimTestFactory.cs

@@ -193,6 +193,7 @@ internal sealed class SVSimTestFactory : WebApplicationFactory<Program>
         // Wired here so SeedGlobalsAsync callers (e.g. PracticeControllerTests) still see
         // practice-opponent rows after the corresponding block was lifted out of GlobalsImporter.
         await new PracticeOpponentImporter().ImportAsync(ctx, seedDir);
+        await new PaymentItemImporter().ImportAsync(ctx, seedDir);
     }
 
     /// <summary>Convenience: bake the X-Test-Viewer-Id header into a fresh client.</summary>