feat(assets): add DeepSeek assistant with streaming results and voice input

src/modules/assets/assistant/client.ts

@@ -0,0 +1,51 @@
+import { fetchAuthenticated } from "../../../auth/api-client";
+import type {
+  AssistantEvent,
+  QueryPlan,
+} from "../../../shared/assets/assistant";
+
+export async function askAssetAssistant(
+  input: { message: string; subject: string | null; previous?: QueryPlan },
+  signal: AbortSignal,
+  onEvent: (event: AssistantEvent) => void,
+) {
+  const response = await fetchAuthenticated("/api/asset-assistant/ask", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(input),
+    signal,
+  });
+  if (!response.ok) {
+    const body = await response.json().catch(() => null);
+    throw new Error(body?.error || "查询服务暂时不可用。");
+  }
+  if (!response.body) throw new Error("当前浏览器无法读取查询进度。");
+  const reader = response.body.getReader();
+  const decoder = new TextDecoder();
+  let buffer = "",
+    completed = false;
+  try {
+    while (true) {
+      const { value, done } = await reader.read();
+      buffer += decoder.decode(value, { stream: !done });
+      const frames = buffer.split(/\r?\n\r?\n/);
+      buffer = frames.pop() || "";
+      for (const frame of frames) {
+        const data = frame
+          .split(/\r?\n/)
+          .filter((line) => line.startsWith("data:"))
+          .map((line) => line.slice(5).trim())
+          .join("\n");
+        if (!data) continue;
+        const event = JSON.parse(data) as AssistantEvent;
+        if (event.type === "result" || event.type === "error") completed = true;
+        onEvent(event);
+      }
+      if (done) break;
+    }
+    if (!completed && !signal.aborted)
+      throw new Error("连接中断，请重新提问。");
+  } finally {
+    reader.releaseLock();
+  }
+}