feat(lesson-preparation): major update with AI features, schedules, and new components

- Add actions-schedules.ts and data-access-schedules.ts for schedule management

- Add AI differentiation, AI feedback, consistency check dialogs

- Add attachment-picker, curriculum-heatmap, print-view, version-diff-view

- Add lesson-plan-mobile-view and schedule-dialog components

- Add lib: ai-differentiation, ai-feedback, auto-layout, consistency-check,

  curriculum-coverage, export, version-diff

- Add history-slice hook for version history

- Update existing components, hooks, providers, services, types

- Add teacher lesson-plans heatmap and library pages

src/modules/lesson-preparation/lib/ai-feedback.ts

@@ -0,0 +1,135 @@
+/**
+ * V5-17 A1/A2：AI 反馈闭环 + 解释性展示。
+ *
+ * 调用 AI 对课案文档进行教学评一致性反馈，返回结构化建议。
+ * 反馈包含：
+ * - strengths：课案优点
+ * - improvements：改进建议
+ * - alignment：教学评一致性评估
+ * - differentiation：差异化教学建议
+ *
+ * 每条建议附带 reason（解释性展示），帮助教师理解 AI 判断依据。
+ */
+import "server-only";
+import { env } from "@/env.mjs";
+import { createAiChatCompletion } from "@/shared/lib/ai";
+import { isRecord } from "@/shared/lib/type-guards";
+import { z } from "zod";
+import type { LessonPlanDocument, LessonPlanNode } from "../types";
+
+/** AI 反馈单条建议 */
+export interface AiFeedbackItem {
+  /** i18n 键后缀（feedback.* 命名空间下） */
+  category: "strengths" | "improvements" | "alignment" | "differentiation";
+  /** 建议标题 */
+  title: string;
+  /** 解释性理由（A2：解释性展示） */
+  reason: string;
+  /** 关联节点 ID（如适用） */
+  nodeId?: string;
+}
+
+/** AI 反馈结果 */
+export interface AiFeedbackResult {
+  items: AiFeedbackItem[];
+  /** 整体评分（0-100） */
+  overallScore: number;
+  /** 摘要 */
+  summary: string;
+}
+
+const FeedbackItemSchema = z.object({
+  category: z.enum(["strengths", "improvements", "alignment", "differentiation"]),
+  title: z.string().min(1),
+  reason: z.string(),
+  nodeId: z.string().optional(),
+});
+
+const FeedbackResultSchema = z.object({
+  items: z.array(FeedbackItemSchema),
+  overallScore: z.number().min(0).max(100),
+  summary: z.string(),
+});
+
+const AI_FEEDBACK_PROMPT_TEMPLATE = `你是资深教学设计专家。请对以下课案文档进行教学评一致性评估，给出结构化反馈。
+
+课案文档（JSON）：
+---
+{doc}
+---
+
+请从四个维度评估：
+1. strengths：课案优点
+2. improvements：改进建议
+3. alignment：教学评一致性（目标-教学-评价是否对齐）
+4. differentiation：差异化教学建议
+
+返回 JSON 对象，含：
+- items：数组，每项含 category（维度）/title（建议标题）/reason（解释性理由，说明为何给出此建议）/nodeId（关联节点 ID，可选）
+- overallScore：整体评分 0-100
+- summary：一句话摘要
+
+注意：reason 字段必须解释判断依据，帮助教师理解。`;
+
+/** 安全提取节点文本用于 AI prompt */
+function extractNodeText(node: LessonPlanNode): string {
+  const data = node.data as unknown;
+  if (!isRecord(data)) return "";
+  const html = typeof data.html === "string" ? data.html : "";
+  const sourceText = typeof data.sourceText === "string" ? data.sourceText : "";
+  return html || sourceText || "";
+}
+
+/**
+ * 调用 AI 对课案文档生成结构化反馈。
+ *
+ * @param doc 课案文档
+ * @returns AI 反馈结果；AI 不可用时返回空结果
+ */
+export async function generateLessonPlanFeedback(
+  doc: LessonPlanDocument,
+): Promise<AiFeedbackResult> {
+  // 提取教学节点摘要（排除正文节点，控制 token 用量）
+  const teachingNodes = doc.nodes.filter(
+    (n): n is LessonPlanNode => n.type !== "textbook_content",
+  );
+  if (teachingNodes.length === 0) {
+    return { items: [], overallScore: 0, summary: "" };
+  }
+
+  const docSummary = teachingNodes.slice(0, 20).map((n) => ({
+    id: n.id,
+    type: n.type,
+    title: n.title,
+    stage: n.stage,
+    differentiation: n.differentiation,
+    text: extractNodeText(n).slice(0, 200),
+  }));
+
+  const prompt = AI_FEEDBACK_PROMPT_TEMPLATE.replace(
+    "{doc}",
+    JSON.stringify(docSummary),
+  );
+
+  try {
+    const { content } = await createAiChatCompletion({
+      messages: [{ role: "user", content: prompt }],
+      model: env.AI_MODEL ?? "gpt-4o-mini",
+      temperature: 0.4,
+    });
+
+    // 从返回内容中提取 JSON 对象
+    const jsonMatch = content.match(/\{[\s\S]*\}/);
+    if (!jsonMatch) return { items: [], overallScore: 0, summary: "" };
+
+    const parsed: unknown = JSON.parse(jsonMatch[0]);
+    const validated = FeedbackResultSchema.safeParse(parsed);
+    if (!validated.success) {
+      return { items: [], overallScore: 0, summary: "" };
+    }
+
+    return validated.data;
+  } catch {
+    return { items: [], overallScore: 0, summary: "" };
+  }
+}