FEAT-13: Abgabe wizard (/vertraege/neu, 4 steps, ?tiere= prefill), Vertraege list w/ download+delete, /einstellungen Zuchtprofil form, contracts/settings API clients, nav entries, detail-page entry point + replace orphaned contactInfo with email/phone/address across Kontakt pages

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

gerbil-manager-web/src/api/contracts.ts

@@ -0,0 +1,42 @@
+/** FEAT-13: Abgabeverträge (/contracts). */
+import { API_BASE_URL, api, resources } from './client'
+import { toQueryString, type GridifyQuery } from './gridify'
+import type { DateOnlyString, Paged } from './types'
+
+export interface SaleContract {
+  id: string
+  contactId: string
+  price: number
+  handoverDate: DateOnlyString
+  contractDate: DateOnlyString
+  fileName: string
+  createdAt: string
+  gerbilIds: string[]
+  /** API-relativer Download-Pfad ("/contracts/{id}/file"). */
+  url: string
+}
+
+export interface CreateSaleContract {
+  contactId: string
+  gerbilIds: string[]
+  price: number
+  handoverDate: DateOnlyString
+  contractDate?: DateOnlyString | null
+}
+
+export function listContracts(query: GridifyQuery): Promise<Paged<SaleContract>> {
+  return api.get<Paged<SaleContract>>(`${resources.contracts}${toQueryString(query)}`)
+}
+
+export function createContract(body: CreateSaleContract): Promise<SaleContract> {
+  return api.post<SaleContract>(resources.contracts, body)
+}
+
+export function deleteContract(id: string): Promise<void> {
+  return api.delete(`${resources.contracts}/${id}`)
+}
+
+/** Absolute Download-URL der .docx (für <a href> / window.open). */
+export function contractFileUrl(contract: Pick<SaleContract, 'url'>): string {
+  return `${API_BASE_URL}${contract.url}`
+}