Merge lane/abrechnung in feature/craftvia-mvp

Konflikte gelöst (additiv): Benachrichtigungstexte (Planung + Meilensteine), Event-Typen,
Navigation, Job-Queues/Prozessoren (geocode-site, planning-watch, billing-pdf), OpenAPI-Tags,
Smoke-Prüfungen (zweiter Mandant: Planung + Abrechnung).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

prisma/schema.prisma

@@ -750,6 +750,8 @@ model WorkOrder {
   voiceNotes        VoiceNote[]
   reports           Report[]
   documents         Document[]
+  milestones        WorkOrderMilestone[] // L14
+  billingRecords    BillingRecord[] // L14
 
   @@unique([tenantId, number])
   @@index([tenantId, status])
@@ -872,6 +874,8 @@ model MaterialUsage {
   photoId         String?             @map("photo_id")
   recordedById    String?             @map("recorded_by_id")
   clientId        String?             @map("client_id") // offline local id
+  /// L14: billed billing record containing this position (set on „abgerechnet", cleared on void)
+  billingRecordId String?             @map("billing_record_id")
   createdAt       DateTime            @default(now()) @map("created_at")
   updatedAt       DateTime            @updatedAt @map("updated_at")
 
@@ -879,6 +883,7 @@ model MaterialUsage {
   materialPlan MaterialPlan? @relation(fields: [materialPlanId], references: [id], onDelete: SetNull)
   workSession  WorkSession?  @relation(fields: [workSessionId], references: [id], onDelete: SetNull)
 
+  @@index([tenantId, billingRecordId])
   @@index([tenantId, workOrderId])
   @@unique([tenantId, clientId])
   @@map("material_usages")
@@ -966,11 +971,14 @@ model TimeEntry {
   /// proposed correction of this entry {startedAt, endedAt, type, reason, requestedAt}; old values stay valid until approval
   pendingChange    Json?              @map("pending_change")
   note             String?
+  /// L14: billed billing record containing this entry (set on „abgerechnet", cleared on void)
+  billingRecordId  String?            @map("billing_record_id")
   createdAt        DateTime      @default(now()) @map("created_at")
   updatedAt        DateTime      @updatedAt @map("updated_at")
 
   workSession WorkSession @relation(fields: [workSessionId], references: [id], onDelete: Cascade)
 
+  @@index([tenantId, billingRecordId])
   @@index([tenantId, workSessionId])
   @@index([tenantId, userId, startedAt])
   @@index([tenantId, approvalStatus])
@@ -1341,3 +1349,87 @@ model AiGeneration {
   @@index([tenantId, entityType, entityId])
   @@map("ai_generations")
 }
+
+// ---------- L14 Abrechnungsübersicht (keine Buchhaltung: keine Preise/Beträge/Steuern) ----------
+
+enum MilestoneStatus {
+  open
+  reached // reported by technician / team lead
+  confirmed // confirmed by back office → billing record
+  billed
+}
+
+enum BillingRecordKind {
+  order_completion
+  milestone
+  daily_report
+}
+
+enum BillingRecordStatus {
+  open
+  billed
+  voided
+}
+
+/// Optional billing section of a work order (defined by back office, reported by the field, confirmed by back office).
+model WorkOrderMilestone {
+  id              String          @id @default(cuid())
+  tenantId        String          @map("tenant_id")
+  workOrderId     String          @map("work_order_id")
+  title           String
+  description     String?
+  sortOrder       Int             @default(0) @map("sort_order")
+  status          MilestoneStatus @default(open)
+  reachedById     String?         @map("reached_by_id")
+  reachedAt       DateTime?       @map("reached_at")
+  reachedNote     String?         @map("reached_note")
+  confirmedById   String?         @map("confirmed_by_id")
+  confirmedAt     DateTime?       @map("confirmed_at")
+  rejectedById    String?         @map("rejected_by_id")
+  rejectedAt      DateTime?       @map("rejected_at")
+  rejectionReason String?         @map("rejection_reason")
+  /// billed record this milestone belongs to (plain id, no FK)
+  billingRecordId String?         @map("billing_record_id")
+  createdById     String?         @map("created_by_id")
+  createdAt       DateTime        @default(now()) @map("created_at")
+  updatedAt       DateTime        @updatedAt @map("updated_at")
+  deletedAt       DateTime?       @map("deleted_at")
+
+  workOrder WorkOrder @relation(fields: [workOrderId], references: [id], onDelete: Cascade)
+
+  @@index([tenantId, workOrderId])
+  @@index([tenantId, status])
+  @@map("work_order_milestones")
+}
+
+/// Billing overview entry: an order completion, a confirmed milestone or an approved daily report that the
+/// accounting (outside Craftvia) can invoice. `snapshot` freezes the statement when marked as billed.
+/// Partial unique indexes (SQL, migration `*_abrechnung`): one non-voided record per source.
+model BillingRecord {
+  id            String              @id @default(cuid())
+  tenantId      String              @map("tenant_id")
+  workOrderId   String              @map("work_order_id")
+  kind          BillingRecordKind
+  milestoneId   String?             @map("milestone_id")
+  reportId      String?             @map("report_id")
+  periodFrom    DateTime            @map("period_from")
+  periodTo      DateTime            @map("period_to")
+  status        BillingRecordStatus @default(open)
+  snapshot      Json?
+  pdfDocumentId String?             @map("pdf_document_id")
+  pdfChecksum   String?             @map("pdf_checksum")
+  invoiceNumber String?             @map("invoice_number")
+  billedById    String?             @map("billed_by_id")
+  billedAt      DateTime?           @map("billed_at")
+  voidedById    String?             @map("voided_by_id")
+  voidedAt      DateTime?           @map("voided_at")
+  voidReason    String?             @map("void_reason")
+  createdAt     DateTime            @default(now()) @map("created_at")
+  updatedAt     DateTime            @updatedAt @map("updated_at")
+
+  workOrder WorkOrder @relation(fields: [workOrderId], references: [id], onDelete: Cascade)
+
+  @@index([tenantId, status, createdAt])
+  @@index([tenantId, workOrderId])
+  @@map("billing_records")
+}