Usability and test infrastructure updates.

src/index.ts

@@ -1,10 +1,11 @@
 import { serve } from "bun";
+import { tmpdir } from "node:os";
 import { join, normalize, sep } from "node:path";
 import { ensureIcons, ICONS_DIR } from "../scripts/generate-icons.ts";
 import { injectPrecacheManifest } from "./pwa/precache.ts";
 import { auth } from "./server/auth.ts";
 import { AUTH_ENABLED } from "./server/flags.ts";
-import { MAX_UPLOAD_BYTES, transcribe } from "./server/transcribe.ts";
+import { MAX_UPLOAD_BYTES, parseLanguageAndTask, sidecar, transcribe } from "./server/transcribe.ts";
 import { liveWebSocket } from "./server/live.ts";
 import { getFasterWhisperModel } from "./lib/models.ts";
 
@@ -132,15 +133,27 @@ async function handleApiRequest(request: Request, server: any): Promise<Response
       if (!modelId) return new Response("Missing model", { status: 400 });
       const fasterWhisperModel = getFasterWhisperModel(modelId);
       if (!fasterWhisperModel) return new Response("Unknown model", { status: 400 });
-      
+      // Same validation as POST /api/transcribe (D-030-adjacent: never forward
+      // an unvalidated task/language string into the sidecar protocol just
+      // because this entry point is a WebSocket, not JSON over HTTP).
+      const options = parseLanguageAndTask(url);
+      if (typeof options === "string") return new Response(options, { status: 400 });
+      // Fail fast like the HTTP route (D-013 "degrade gracefully") instead of
+      // opening a socket that can only report unavailability once the first
+      // segment reaches the sidecar.
+      const status = await sidecar.status();
+      if (!status.available) {
+        return new Response(status.reason ?? "server engine unavailable", { status: 503 });
+      }
+
       const success = server.upgrade(request, {
         data: {
           user,
           model: fasterWhisperModel,
-          language: url.searchParams.get("language") || undefined,
-          task: url.searchParams.get("task") || undefined,
-          tempDir: require("node:os").tmpdir()
-        }
+          language: options.language,
+          task: options.task,
+          tempDir: tmpdir(),
+        },
       });
       if (success) return undefined;
       return new Response("WebSocket upgrade failed", { status: 500 });
@@ -310,7 +323,7 @@ options.port = process.env.PORT || 3000;
 // Bun's default cap is 128 MB, which would 4xx a /api/transcribe upload of
 // more than ~35 minutes of raw PCM before the route's own limit applies.
 options.maxRequestBodySize = MAX_UPLOAD_BYTES;
-options.websocket = liveWebSocket as any;
+options.websocket = liveWebSocket;
 
 const server = serve(options);