feat(lesson-preparation): add anchor canvas design, new blocks, and textbook content node

- Add anchor injector for canvas-based anchor positioning

- Add new block components: blackboard, homework, import, key-point, new-teaching, objective, summary

- Add textbook content node for React Flow canvas

- Update actions (kp, publish, main), data-access (templates, versions, main)

- Update editor, node-editor, block-renderer, and picker components

- Update schema, types, hooks, and lib utilities (document-migration, node-summary, rf-mappers)

src/modules/lesson-preparation/components/blocks/summary-block.tsx

@@ -0,0 +1,78 @@
+"use client";
+
+import { useTranslations } from "next-intl";
+import { Plus, Trash2 } from "lucide-react";
+import type { SummaryBlockData } from "../../types";
+import { Button } from "@/shared/components/ui/button";
+
+interface Props {
+  data: SummaryBlockData;
+  onUpdate: (data: SummaryBlockData) => void;
+}
+
+export function SummaryBlock({ data, onUpdate }: Props) {
+  const t = useTranslations("lessonPreparation");
+
+  function updatePoint(index: number, value: string) {
+    const next = data.summaryPoints.map((p, i) => (i === index ? value : p));
+    onUpdate({ ...data, summaryPoints: next });
+  }
+
+  function addPoint() {
+    onUpdate({
+      ...data,
+      summaryPoints: [...data.summaryPoints, ""],
+    });
+  }
+
+  function removePoint(index: number) {
+    onUpdate({
+      ...data,
+      summaryPoints: data.summaryPoints.filter((_, i) => i !== index),
+    });
+  }
+
+  return (
+    <div className="space-y-2">
+      <div className="text-xs text-on-surface-variant">
+        {t("summary.hint")}
+      </div>
+      {data.summaryPoints.map((point, idx) => (
+        <div key={idx} className="flex items-start gap-2">
+          <span className="text-xs text-on-surface-variant mt-1">{idx + 1}.</span>
+          <input
+            type="text"
+            value={point}
+            onChange={(e) => updatePoint(idx, e.target.value)}
+            className="flex-1 text-sm border border-outline-variant rounded px-2 py-1"
+            placeholder={t("summary.pointPlaceholder")}
+          />
+          <Button
+            variant="ghost"
+            size="sm"
+            className="!p-1 text-error"
+            onClick={() => removePoint(idx)}
+            aria-label={t("action.delete")}
+          >
+            <Trash2 className="w-3 h-3" />
+          </Button>
+        </div>
+      ))}
+      <Button variant="outline" size="sm" onClick={addPoint}>
+        <Plus className="w-3 h-3 mr-1" />
+        {t("summary.addPoint")}
+      </Button>
+      <div>
+        <label className="text-xs font-medium block mb-1 mt-2">
+          {t("summary.homeworkPreviewLabel")}
+        </label>
+        <textarea
+          value={data.homeworkPreview}
+          onChange={(e) => onUpdate({ ...data, homeworkPreview: e.target.value })}
+          className="w-full text-sm border border-outline-variant rounded px-2 py-1 resize-y min-h-[40px]"
+          placeholder={t("summary.homeworkPreviewPlaceholder")}
+        />
+      </div>
+    </div>
+  );
+}