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/objective-block.tsx

@@ -0,0 +1,87 @@
+"use client";
+
+import { useTranslations } from "next-intl";
+import { Plus, Trash2 } from "lucide-react";
+import type { ObjectiveBlockData, ObjectiveItem } from "../../types";
+import { Button } from "@/shared/components/ui/button";
+
+interface Props {
+  data: ObjectiveBlockData;
+  onUpdate: (data: ObjectiveBlockData) => void;
+}
+
+const DIMENSIONS: ObjectiveItem["dimension"][] = ["knowledge", "process", "emotion"];
+
+export function ObjectiveBlock({ data, onUpdate }: Props) {
+  const t = useTranslations("lessonPreparation");
+
+  function updateItem(index: number, patch: Partial<ObjectiveItem>) {
+    const next = data.objectives.map((it, i) =>
+      i === index ? { ...it, ...patch } : it,
+    );
+    onUpdate({ ...data, objectives: next });
+  }
+
+  function addItem() {
+    onUpdate({
+      ...data,
+      objectives: [
+        ...data.objectives,
+        { dimension: "knowledge", text: "" },
+      ],
+    });
+  }
+
+  function removeItem(index: number) {
+    onUpdate({
+      ...data,
+      objectives: data.objectives.filter((_, i) => i !== index),
+    });
+  }
+
+  return (
+    <div className="space-y-2">
+      <div className="text-xs text-on-surface-variant">
+        {t("objective.hint")}
+      </div>
+      {data.objectives.map((item, idx) => (
+        <div key={idx} className="flex items-start gap-2">
+          <select
+            value={item.dimension}
+            onChange={(e) =>
+              updateItem(idx, {
+                dimension: e.target.value as ObjectiveItem["dimension"],
+              })
+            }
+            className="text-xs border border-outline-variant rounded px-1 py-1 bg-surface"
+          >
+            {DIMENSIONS.map((d) => (
+              <option key={d} value={d}>
+                {t(`objective.dimension.${d}`)}
+              </option>
+            ))}
+          </select>
+          <textarea
+            value={item.text}
+            onChange={(e) => updateItem(idx, { text: e.target.value })}
+            className="flex-1 text-sm border border-outline-variant rounded px-2 py-1 resize-y min-h-[40px]"
+            placeholder={t("objective.textPlaceholder")}
+          />
+          <Button
+            variant="ghost"
+            size="sm"
+            className="!p-1 text-error"
+            onClick={() => removeItem(idx)}
+            aria-label={t("action.delete")}
+          >
+            <Trash2 className="w-3 h-3" />
+          </Button>
+        </div>
+      ))}
+      <Button variant="outline" size="sm" onClick={addItem}>
+        <Plus className="w-3 h-3 mr-1" />
+        {t("objective.addItem")}
+      </Button>
+    </div>
+  );
+}