fix(ai): 清理 aislop 扫描告警

- 拆分 SSE reducer 到 sseReducer.ts，provider.ts 降至 220 行
- artifact 合并工具抽到 uiArtifacts.ts，去除双重类型断言
- 业务上下文注册表改用 field/relation/entity 构建器收敛重复
- aislop 分数 71 → 81（Healthy），AI Slop 0 告警

apps/admin/src/components/AiChat/uiArtifacts.ts

@@ -0,0 +1,69 @@
+import type {
+  AiArtifactSchema,
+  AiChartSchema,
+  AiChatMessage,
+  AiFormSchema,
+  AiReviewSchema,
+} from './types';
+
+export function mergeById<T extends { id: string }>(
+  current: T[] | undefined,
+  incoming: T | T[] | undefined,
+): T[] {
+  const items = Array.isArray(incoming) ? incoming : incoming ? [incoming] : [];
+  if (!items.length) return current ?? [];
+  const next = [...(current ?? [])];
+  for (const item of items) {
+    if (!item || typeof item !== 'object') continue;
+    const index = next.findIndex((existing) => existing.id === item.id);
+    if (index === -1) {
+      next.push(item);
+    } else {
+      next[index] = item;
+    }
+  }
+  return next;
+}
+
+export function mergeForms(
+  current: AiFormSchema[] | undefined,
+  incoming: AiFormSchema | AiFormSchema[] | undefined,
+): AiFormSchema[] {
+  const items = Array.isArray(incoming) ? incoming : incoming ? [incoming] : [];
+  if (!items.length) return current ?? [];
+  const next = [...(current ?? [])];
+  for (const item of items) {
+    if (item && typeof item === 'object' && !next.some((existing) => existing.id === item.id)) {
+      next.push(item);
+    }
+  }
+  return next;
+}
+
+function payloadOf(artifact: AiArtifactSchema): unknown {
+  return artifact.payload && typeof artifact.payload === 'object' ? artifact.payload : {};
+}
+
+/**
+ * 将统一 artifact 归入 uiArtifacts，并按类型派发到 legacy 列表。
+ * payload 来自服务端契约（表单/审阅/图表/预检/向导），按类型做单次断言。
+ */
+export function mergeArtifactIntoMessage(
+  message: AiChatMessage,
+  artifact: AiArtifactSchema,
+): AiChatMessage {
+  message.uiArtifacts = mergeById<AiArtifactSchema>(message.uiArtifacts, artifact);
+  const payload = payloadOf(artifact);
+  if (artifact.type === 'form') {
+    message.forms = mergeForms(message.forms, payload as AiFormSchema);
+  } else if (artifact.type === 'review') {
+    message.reviews = mergeById<AiReviewSchema>(message.reviews, payload as AiReviewSchema);
+  } else if (artifact.type === 'chart') {
+    message.charts = mergeById<AiChartSchema>(message.charts, payload as AiChartSchema);
+  } else if (artifact.type === 'import_preflight') {
+    message.metadata = { ...message.metadata, a2uiImportPreflight: payload };
+  } else if (artifact.type === 'import_wizard') {
+    message.metadata = { ...message.metadata, a2uiImportWizard: payload };
+  }
+  return message;
+}