refactor: flatten monorepo to single web package (#12)

Flatten the pnpm monorepo (apps/web + packages/*) into a single web package at the repo root.

- Move app/lib/components/scripts/public to root; drop apps/web and packages/* wrappers
- Rewrite tsconfig paths (@infiplot/*) to ./lib/*; turbopack.root = __dirname
- Update Vercel (no root-directory) and Cloudflare (pnpm build:cf at root) deploy paths
- Regenerate pnpm-lock.yaml to drop stale workspace importers
- Bump engines.node to >=22 to match wrangler

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

lib/tts-client/index.ts

@@ -0,0 +1 @@
+export { xiaomiProvision as provisionVoice, xiaomiSynthesize as synthesize } from "./xiaomi";

lib/tts-client/xiaomi.ts

@@ -0,0 +1,115 @@
+import type { CharacterVoice, TtsConfig } from "@infiplot/types";
+
+// Xiaomi MiMo currently outputs wav / pcm16 only (mp3 not supported for output).
+// The reference clip we persist is therefore wav. Kept as a single switch so we
+// can flip to mp3 the day the API supports it.
+const OUTPUT_FORMAT = "wav";
+const OUTPUT_MIME = "audio/wav";
+
+function buildHeaders(cfg: TtsConfig): HeadersInit {
+  return {
+    "Content-Type": "application/json",
+    "api-key": cfg.apiKey,
+  };
+}
+
+function joinUrl(baseUrl: string, path: string): string {
+  return `${baseUrl.replace(/\/$/, "")}${path}`;
+}
+
+function designModel(cfg: TtsConfig): string {
+  return `${cfg.speechModel}-voicedesign`;
+}
+
+function cloneModel(cfg: TtsConfig): string {
+  return `${cfg.speechModel}-voiceclone`;
+}
+
+type ChatAudioResponse = {
+  choices?: Array<{ message?: { audio?: { data?: string } } }>;
+  error?: { message?: string };
+  message?: string;
+};
+
+function extractAudio(json: ChatAudioResponse, where: string): string {
+  const data = json.choices?.[0]?.message?.audio?.data;
+  if (!data) {
+    const err = json.error?.message ?? json.message ?? JSON.stringify(json);
+    throw new Error(`Xiaomi ${where} returned no audio: ${err.slice(0, 300)}`);
+  }
+  return data;
+}
+
+export async function xiaomiProvision(
+  cfg: TtsConfig,
+  description: string,
+): Promise<CharacterVoice> {
+  const url = joinUrl(cfg.baseUrl, "/chat/completions");
+
+  const body = {
+    model: designModel(cfg),
+    messages: [
+      { role: "user", content: description },
+      { role: "assistant", content: "你好，这是音色试听样本。" },
+    ],
+    audio: { format: OUTPUT_FORMAT },
+  };
+
+  const res = await fetch(url, {
+    method: "POST",
+    headers: buildHeaders(cfg),
+    body: JSON.stringify(body),
+  });
+
+  if (!res.ok) {
+    const text = await res.text();
+    throw new Error(`Xiaomi voicedesign ${res.status}: ${text.slice(0, 300)}`);
+  }
+
+  const json = (await res.json()) as ChatAudioResponse;
+  const referenceAudioBase64 = extractAudio(json, "voicedesign");
+
+  return { provider: "xiaomi", referenceAudioBase64, mimeType: OUTPUT_MIME };
+}
+
+export async function xiaomiSynthesize(
+  cfg: TtsConfig,
+  voice: CharacterVoice,
+  text: string,
+  delivery?: string,
+  signal?: AbortSignal,
+): Promise<{ audioBase64: string; mimeType: string }> {
+  const url = joinUrl(cfg.baseUrl, "/chat/completions");
+
+  // The free-form delivery direction rides in the `user` (director) message,
+  // so it shapes the performance without ever being read aloud. The spoken
+  // text stays in the `assistant` message, clean.
+  const body = {
+    model: cloneModel(cfg),
+    messages: [
+      { role: "user", content: delivery?.trim() ?? "" },
+      { role: "assistant", content: text },
+    ],
+    audio: {
+      format: OUTPUT_FORMAT,
+      voice: `data:${voice.mimeType};base64,${voice.referenceAudioBase64}`,
+    },
+  };
+
+  const res = await fetch(url, {
+    method: "POST",
+    headers: buildHeaders(cfg),
+    body: JSON.stringify(body),
+    signal,
+  });
+
+  if (!res.ok) {
+    const txt = await res.text();
+    throw new Error(`Xiaomi voiceclone ${res.status}: ${txt.slice(0, 300)}`);
+  }
+
+  const json = (await res.json()) as ChatAudioResponse;
+  const audioBase64 = extractAudio(json, "voiceclone");
+
+  return { audioBase64, mimeType: OUTPUT_MIME };
+}