feat: add project-aware agent workspace

src/shared/ai-elements/persona-resource.ts

@@ -0,0 +1,61 @@
+import asset from "./persona-resource-manifest.json";
+
+const source = `${asset.path}?v=${asset.sha256}`;
+const cacheName = "tjwater-agent-persona-v1";
+
+let pending: Promise<ArrayBuffer> | undefined;
+
+async function readResource(response: Response): Promise<ArrayBuffer> {
+  if (!response.ok) throw new Error(`Obsidian resource: ${response.status}`);
+  const bytes = await response.arrayBuffer();
+  const header = new Uint8Array(bytes, 0, Math.min(bytes.byteLength, 4));
+  if (bytes.byteLength !== asset.byteLength || String.fromCharCode(...header) !== "RIVE") {
+    throw new Error("Obsidian resource: invalid animation data");
+  }
+  if (globalThis.crypto?.subtle) {
+    const digest = await crypto.subtle.digest("SHA-256", bytes);
+    const hash = Array.from(new Uint8Array(digest), (byte) => byte.toString(16).padStart(2, "0")).join("");
+    if (hash !== asset.sha256) throw new Error("Obsidian resource: version mismatch");
+  }
+  return bytes;
+}
+
+async function loadBytes(): Promise<ArrayBuffer> {
+  let cache: Cache | undefined;
+  try {
+    cache = await globalThis.caches?.open(cacheName);
+    const cached = await cache?.match(source);
+    if (cached) return await readResource(cached);
+  } catch {
+    // Storage can be denied or contain incomplete data. Retry through the network.
+  }
+
+  const response = await fetch(source, { signal: AbortSignal.timeout(15_000) });
+  const bytes = await readResource(response);
+  if (cache) {
+    try {
+      await cache.put(source, new Response(bytes, {
+        headers: { "Content-Type": "application/octet-stream" }
+      }));
+      const current = new URL(source, window.location.href);
+      for (const request of await cache.keys()) {
+        const url = new URL(request.url);
+        if (url.origin === current.origin && url.pathname === asset.path && url.href !== current.href) {
+          await cache.delete(request);
+        }
+      }
+    } catch {
+      // Quota or storage failures must not prevent the downloaded animation playing.
+    }
+  }
+  return bytes;
+}
+
+// Share the immutable bytes, never a live renderer or View Model instance.
+export function loadPersonaResource() {
+  pending ??= loadBytes().catch((error: unknown) => {
+    pending = undefined;
+    throw error;
+  });
+  return pending;
+}