feat(agent): add voice input and photo attachments to assistant

Wire mic through Whisper-compatible transcriptions on LLM_BASE_URL.

Photos upload to MinIO and reach the vision model as base64 image_url parts.

src/app/api/agent/chat/route.ts

@@ -1,24 +1,11 @@
-import { z } from "zod";
 import { apiError, apiJson } from "@/lib/api-handler";
 import { resolveApiAuth } from "@/lib/api-auth";
 import { getAssistantPreferences, resolveAssistantSystemPrompt } from "@/lib/assistant-preference";
 import { isLlmConfigured } from "@/lib/llm";
+import { clientChatInputSchema } from "@/modules/agent/messages";
 import { encodeSseEvent } from "@/modules/agent/server/progress";
 import { runAgentChat } from "@/modules/agent/server/run";
 
-const chatInput = z.object({
-  stream: z.boolean().optional(),
-  messages: z
-    .array(
-      z.object({
-        role: z.enum(["user", "assistant"]),
-        content: z.string().trim().min(1).max(8000),
-      }),
-    )
-    .min(1)
-    .max(40),
-});
-
 export async function POST(request: Request) {
   const auth = await resolveApiAuth(request);
   if (!auth?.userId) {
@@ -39,7 +26,7 @@ export async function POST(request: Request) {
     return apiError("Invalid JSON body", 400);
   }
 
-  const parsed = chatInput.safeParse(body);
+  const parsed = clientChatInputSchema.safeParse(body);
   if (!parsed.success) {
     return apiError(parsed.error.issues[0]?.message ?? "Validation error", 400);
   }

src/app/api/agent/transcribe/route.ts

@@ -0,0 +1,51 @@
+import { apiError, apiJson } from "@/lib/api-handler";
+import { resolveApiAuth } from "@/lib/api-auth";
+import { getAssistantPreferences } from "@/lib/assistant-preference";
+import { transcribeAudioFile } from "@/lib/llm/transcribe";
+
+export const runtime = "nodejs";
+export const maxDuration = 120;
+
+const MAX_AUDIO_BYTES = 25 * 1024 * 1024;
+
+export async function POST(request: Request) {
+  const auth = await resolveApiAuth(request);
+  if (!auth?.userId) {
+    return apiError("Unauthorized", 401);
+  }
+
+  const assistant = await getAssistantPreferences(auth.userId);
+  if (!assistant.enabled) {
+    return apiError("Assistant not enabled", 403);
+  }
+
+  let formData: FormData;
+  try {
+    formData = await request.formData();
+  } catch {
+    return apiError("Invalid multipart body", 400);
+  }
+
+  const file = formData.get("file");
+  if (!(file instanceof File)) {
+    return apiError("No audio file in request", 400);
+  }
+
+  if (!file.type.startsWith("audio/") && file.type !== "video/webm") {
+    return apiError("Only audio recordings are allowed", 415);
+  }
+
+  if (file.size > MAX_AUDIO_BYTES) {
+    return apiError("Recording exceeds 25 MB limit", 413);
+  }
+
+  const filename = file.name.trim() || "recording.wav";
+
+  try {
+    const text = await transcribeAudioFile(file, filename);
+    return apiJson({ text });
+  } catch (err) {
+    const message = err instanceof Error ? err.message : "Transcription failed";
+    return apiError(message, 502);
+  }
+}

src/app/api/uploads/route.ts

@@ -33,7 +33,9 @@ export async function POST(request: Request) {
   }
 
   const url = new URL(request.url);
-  const scope = url.searchParams.get("scope") === "notes" ? "notes" : "garden";
+  const scopeParam = url.searchParams.get("scope");
+  const scope =
+    scopeParam === "notes" ? "notes" : scopeParam === "assistant" ? "assistant" : "garden";
 
   if (!file.type.startsWith("image/")) {
     return NextResponse.json({ error: "Only image files are allowed" }, { status: 415 });