feat(sprint8): Phase 5+6 — Integration, schedulers, tier enforcement, testing

Phase 5 — Integration:
- PaymentReminderScheduler: monthly cron at 9am, sends PAYMENT_REMINDER
  and PAYMENT_OVERDUE (30+ days) notifications, audit logged
- BoardTermScheduler: daily cron at 8am, sends BOARD_TERM_EXPIRING
  notification 30 days before term end (1-day window for single delivery)
- Assembly protocol auto-archive: completeAssembly() generates PDF via
  AssemblyProtocolService and stores it in DocumentService.archiveProtocol()
- PlanTierService: Sprint 8 limits added (Kassenbuch 3mo starter, 1 MV/year
  starter, 100MB/1GB/unlimited document storage)
- Notification wiring: PAYMENT_RECEIVED sent to member on recordPayment(),
  sendToAllMembers() added to NotificationService for assembly invitations
- Seed data: 2 fee schedules (Regular €30, Reduced €15), 4 fee assignments,
  3 sample payments, 2 board positions, 2 board members

Phase 6 — Testing infrastructure:
- V22 migration: protocol_document_id on assemblies table
- Schedulers disabled in test profile (cannamanage.schedulers.enabled=false)
- Scheduler property configurable via SCHEDULERS_ENABLED env var

Additional fixes (pre-existing Phase 4 issues):
- AssemblyProtocolService: fixed Document import ambiguity (OpenPDF vs entity)
- AuditService: added convenience overloads for UUID actorId/clubId
- ReceiptPdfService: fixed getReceiptNumber/getMemberNumber/getPaymentDate
- StaffPermissionChecker: added getUserId/getClubId/getTenantId helpers
- FinanceService: added getPaymentById, exportLedgerCsv methods

cannamanage-domain/src/main/java/de/cannamanage/domain/entity/Assembly.java

@@ -55,6 +55,9 @@ public class Assembly extends AbstractTenantEntity {
     @Column(name = "closed_at")
     private Instant closedAt;
 
+    @Column(name = "protocol_document_id")
+    private UUID protocolDocumentId;
+
     @Column(name = "created_by", nullable = false)
     private UUID createdBy;
 
@@ -104,6 +107,9 @@ public class Assembly extends AbstractTenantEntity {
     public UUID getCreatedBy() { return createdBy; }
     public void setCreatedBy(UUID createdBy) { this.createdBy = createdBy; }
 
+    public UUID getProtocolDocumentId() { return protocolDocumentId; }
+    public void setProtocolDocumentId(UUID protocolDocumentId) { this.protocolDocumentId = protocolDocumentId; }
+
     public Instant getUpdatedAt() { return updatedAt; }
     public void setUpdatedAt(Instant updatedAt) { this.updatedAt = updatedAt; }
 }