Initial commit: AI-driven visual novel scaffold

- Monorepo (pnpm workspace): apps/web + packages/{types,ai-client,engine}
- Next.js 16 web app with three-stage AI orchestration
- Three independently configurable providers: text LLM, image generator, vision model
- Warm minimalist editorial UI design
- One-click Vercel deploy ready

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/ai-client/src/image.ts

@@ -0,0 +1,44 @@
+import type { ProviderConfig } from "@dada/types";
+
+export async function generateImage(
+  config: ProviderConfig,
+  prompt: string,
+  opts?: { size?: string; quality?: "low" | "medium" | "high" | "auto" },
+): Promise<string> {
+  const url = `${config.baseUrl.replace(/\/$/, "")}/images/generations`;
+  const body: Record<string, unknown> = {
+    model: config.model,
+    prompt,
+    size: opts?.size ?? "1024x1536",
+    quality: opts?.quality ?? "medium",
+    n: 1,
+  };
+
+  const res = await fetch(url, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      Authorization: `Bearer ${config.apiKey}`,
+    },
+    body: JSON.stringify(body),
+  });
+
+  if (!res.ok) {
+    const text = await res.text();
+    throw new Error(`Image API error ${res.status}: ${text}`);
+  }
+
+  const json = (await res.json()) as {
+    data: { b64_json?: string; url?: string }[];
+  };
+  const item = json.data[0];
+  if (!item) throw new Error("Image API returned no data");
+
+  if (item.b64_json) return item.b64_json;
+  if (item.url) {
+    const imgRes = await fetch(item.url);
+    const buf = await imgRes.arrayBuffer();
+    return Buffer.from(buf).toString("base64");
+  }
+  throw new Error("Image API returned neither b64_json nor url");
+}