L14 Abrechnungsübersicht: Services für Einträge, Aufstellung, Abrechnen/Stornieren, Meilensteine und PDF

syncBillingCandidates (idempotent, Event-Hook für work_order.released_for_billing und report.approved), Aufstellung ohne Preise (nur freigegebene Zeiten, Fahrzeit getrennt, Pausen informativ, Anfahrten-Zählung, Material), markBilled mit eingefrorenem Snapshot und Positionszuordnung, voidBilling mit Grund und neuem offenen Eintrag (billed → released_for_billing nur über applyTransition-Option billingVoid), Meilenstein-Flow mit Events, Job billing-pdf (Dokument other/backoffice_only), Sync-Op milestone.reach.

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

messages/en/notifications.json

@@ -48,7 +48,10 @@
     "sync_failed": "Sync failed",
     "time_approval_requested": "Time to approve",
     "time_approved": "Time approved",
-    "time_rejected": "Time rejected"
+    "time_rejected": "Time rejected",
+    "milestone_reached": "Milestone reached",
+    "milestone_confirmed": "Milestone confirmed",
+    "milestone_rejected": "Milestone rejected"
   },
   "events": {
     "work_order_assigned": {
@@ -130,6 +133,18 @@
     "time_rejected": {
       "title": "Time rejected: {number}",
       "message": "{actor} rejected your time for {number}: {reason}"
+    },
+    "milestone_reached": {
+      "title": "Milestone reached: {number}",
+      "message": "{actor} reports a milestone of {number} as reached. Please confirm."
+    },
+    "milestone_confirmed": {
+      "title": "Milestone confirmed: {number}",
+      "message": "{actor} confirmed your reported milestone of {number}."
+    },
+    "milestone_rejected": {
+      "title": "Milestone rejected: {number}",
+      "message": "{actor} rejected your reported milestone of {number}: {reason}"
     }
   },
   "fallback": {