Merge feature/inbox-1: Anfragen-Posteingang UI (list/triage/assign/draft/send) [god-QA pending]

# Conflicts:
#	gerbil-manager-web/e2e/mock-data.ts
#	gerbil-manager-web/src/App.tsx

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

@@ -0,0 +1,87 @@
+/**
+ * INBOX-1: Anfragen-Posteingang (/api/requests, Backend INBOX-0/2/3).
+ *
+ * Triage-Hinweis: PUT setzt assignedContactId UNBEDINGT aus dem Input
+ * (Backend überschreibt mit null, wenn das Feld fehlt) — beim reinen
+ * Status-Wechsel also IMMER die aktuelle Zuordnung mitsenden.
+ */
+import { ApiError, api } from './client'
+import { toQueryString, type GridifyQuery } from './gridify'
+import type { Paged } from './types'
+
+/** C#-Enum RequestStatus — Stringnamen auf dem Draht. */
+export type RequestStatus = 'New' | 'InProgress' | 'Assigned' | 'Answered' | 'Abandoned'
+export const REQUEST_STATUSES: RequestStatus[] = [
+  'New',
+  'InProgress',
+  'Assigned',
+  'Answered',
+  'Abandoned',
+]
+
+export interface InboxRequest {
+  id: string
+  gmailMessageId: string
+  threadId: string | null
+  fromAddress: string
+  fromName: string | null
+  subject: string | null
+  bodyText: string | null
+  receivedAt: string
+  status: RequestStatus
+  assignedContactId: string | null
+  draftReply: string | null
+  answeredAt: string | null
+}
+
+export interface RequestTriage {
+  status?: RequestStatus | null
+  assignedContactId?: string | null
+}
+
+/** Ergebnis von POST /api/requests/sync. */
+export interface SyncResult {
+  imported: number
+  /** null = ok; "MailNotConfigured" | "MailAuthFailed" | … */
+  error: string | null
+}
+
+const BASE = '/api/requests'
+
+export function listRequests(query: GridifyQuery): Promise<Paged<InboxRequest>> {
+  return api.get<Paged<InboxRequest>>(`${BASE}${toQueryString(query)}`)
+}
+
+export function getRequest(id: string): Promise<InboxRequest> {
+  return api.get<InboxRequest>(`${BASE}/${id}`)
+}
+
+export function triageRequest(id: string, triage: RequestTriage): Promise<void> {
+  return api.put<void>(`${BASE}/${id}`, triage)
+}
+
+export function syncRequests(): Promise<SyncResult> {
+  return api.post<SyncResult>(`${BASE}/sync`, {})
+}
+
+/** KI-Entwurf erzeugen (INBOX-2); 503 {code:'AiKeyMissing'} solange unkonfiguriert. */
+export function draftReply(id: string): Promise<InboxRequest> {
+  return api.post<InboxRequest>(`${BASE}/${id}/draft`, {})
+}
+
+/** (Bearbeitete) Antwort senden (INBOX-3); setzt serverseitig Answered. */
+export function sendReply(id: string, body: string): Promise<InboxRequest> {
+  return api.post<InboxRequest>(`${BASE}/${id}/send`, { body })
+}
+
+/**
+ * ProblemDetails-Titel aus einem ApiError lesen (Send-Endpunkt meldet
+ * MailNotConfigured/MailAuthFailed über `title`, nicht `code`).
+ */
+export function problemTitle(err: unknown): string | null {
+  if (err instanceof ApiError && err.body && typeof err.body === 'object' && 'title' in err.body) {
+    const title = (err.body as { title: unknown }).title
+    return typeof title === 'string' ? title : null
+  }
+  return null
+}