test(fusion_accounting_bank_rec): performance benchmarks with P95 targets

Tagged 'benchmark' so they can be selected explicitly. Targets:
suggest_matches <500ms, reconcile_batch(50) <5s, list_unreconciled <200ms,
MV refresh <2s. Hard-fail at 5x budget to catch egregious regressions.

Measured on local dev VM:
- suggest_matches: median=221ms p95=234ms (target <500ms)
- reconcile_batch(50 lines): 3318ms (target <5000ms)
- list_unreconciled: median=14ms p95=77ms (target <200ms)
- MV refresh: 60ms (target <2000ms)

Made-with: Cursor

fusion_accounting_bank_rec/tests/__init__.py

@@ -21,3 +21,4 @@ from . import test_bulk_reconcile_wizard
 from . import test_migration_round_trip
 from . import test_coexistence
 from . import test_bank_rec_tours
+from . import test_performance_benchmarks