L16 Lotse-Chat für Monteure: Datenmodell, Provider mit Tool-Schleife, Vorschläge und Bestätigen über bestehende Services

Chatverlauf (LotseConversation/-Message) und Aktionskarten (LotseActionProposal) als
Mandantentabellen mit RLS; Schalter lotseChatEnabled. Tool-Use-Schleife mit Runden- und
Tokengrenze, Datenminimierung per Platzhalter, Auftragszuordnung im Sichtbarkeits-Scope,
Bestätigen/Verwerfen/Alle bestätigen mit Hash, Ablauf und Idempotenz, Transkriptions-API.

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

src/server/services/lotse/chat/transcribe.ts

@@ -0,0 +1,42 @@
+import type { TranscriptionProvider } from "@/server/ai/providers";
+import { getTranscriptionProvider } from "@/server/ai/transcription/openai-compatible";
+import { writeAuditLog } from "@/server/audit";
+import { ServiceError, type ServiceCtx } from "@/server/services/context";
+import { sniffMime } from "@/server/services/field/mime";
+import { assertLotseChatUsable } from "./access";
+
+/**
+ * Microphone key of the Lotse chat (lane L16): audio → text via the existing transcription provider
+ * (L9, Whisper-compatible). The audio is NOT stored — the transcript goes back into the input field
+ * where the technician can edit it before sending. Recorded as AiGeneration (kind `transcription`,
+ * entityType `lotse_chat`) without audio or transcript content, like the L9 voice note transcription.
+ */
+
+export const CHAT_AUDIO_MAX_BYTES = 10 * 1024 * 1024;
+
+export type ChatTranscriptionDeps = { provider: TranscriptionProvider | null };
+export const defaultChatTranscriptionDeps = (): ChatTranscriptionDeps => ({ provider: getTranscriptionProvider() });
+
+export async function transcribeChatAudio(ctx: ServiceCtx, bytes: Buffer, deps: ChatTranscriptionDeps = defaultChatTranscriptionDeps()): Promise<{ text: string }> {
+  await assertLotseChatUsable(ctx);
+  if (!deps.provider) throw new ServiceError("invalid", "transcription not configured", { reason: "not_configured" });
+  if (bytes.byteLength === 0 || bytes.byteLength > CHAT_AUDIO_MAX_BYTES) throw new ServiceError("invalid", "audio size", { reason: "invalid" });
+  const sniffed = sniffMime(bytes);
+  if (!sniffed || sniffed.kind !== "audio") throw new ServiceError("invalid", "not an audio file", { reason: "invalid" });
+
+  let text: string;
+  let meta;
+  try {
+    const res = await deps.provider.transcribe({ bytes, mimeType: sniffed.mime, language: "de" });
+    text = res.text.trim();
+    meta = res.meta;
+  } catch (err) {
+    console.error("[lotse-chat] transcription failed:", (err as Error).message);
+    throw new ServiceError("conflict", "transcription failed", { reason: "provider_failed" });
+  }
+  const generation = await ctx.db.aiGeneration.create({
+    data: { tenantId: ctx.tenantId, kind: "transcription", provider: meta.provider, model: meta.model, entityType: "lotse_chat", entityId: null, input: undefined, output: undefined, createdById: ctx.userId },
+  });
+  await writeAuditLog({ tenantId: ctx.tenantId, actorId: ctx.userId, action: "create", entity: "ai_generation", entityId: generation.id, after: { kind: "transcription", source: "lotse_chat", bytes: bytes.byteLength } });
+  return { text };
+}