feat: add MCP creator screenshot metrics recognition

lib/collection-service.ts

@@ -21,6 +21,33 @@ type ScheduledTask = {
 
 type CollectionSource = "automatic" | "catchup" | "manual";
 
+function userFacingCollectionError(error: unknown) {
+  const message = error instanceof Error ? error.message : String(error ?? "");
+  const normalized = message.toLowerCase();
+  if (
+    /cookie|登录|登陆|授权|access.?token|未登录|未授权|401|403/.test(
+      normalized,
+    )
+  ) {
+    return "采集 Cookie 已过期或无权限";
+  }
+  if (
+    /链接|link|url|404|not found|不存在|删除|失效|无法识别.*笔记/.test(
+      normalized,
+    )
+  ) {
+    return "笔记链接失效或不可访问";
+  }
+  if (
+    /超时|timeout|fetch failed|network|502|503|暂时不可用|响应空/.test(
+      normalized,
+    )
+  ) {
+    return "采集服务暂时不可用";
+  }
+  return "笔记链接失效或采集 Cookie 过期";
+}
+
 function utcDay(value: string) {
   const match = value.match(/^(\d{4})-(\d{2})-(\d{2})$/);
   if (!match) return null;
@@ -311,8 +338,9 @@ export async function collectDistributionMetrics(
     ]);
     return { skipped: false, likes, comments, collects, shares };
   } catch (error) {
-    const message =
-      error instanceof Error ? error.message : "公开数据采集失败";
+    const detail = error instanceof Error ? error.message : String(error);
+    const message = userFacingCollectionError(error);
+    console.error("[KOC LOOP] collection failed", { detail, distributionId });
     await db.batch([
       db
         .prepare(