新增角色管理、世界观设定、章节管理和AI工具调用功能

- 角色管理：CRUD API + 卡片网格UI，每个角色约200字描述
- 世界观设定：单篇长文编辑器，建议500字以上
- 章节管理：CRUD + 排序 API，左右分栏编辑器，单章5000字上限
- AI工具调用：支持工具审批流程和结构化工具调用
- 小说详情页新增章节、角色、世界观入口按钮

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/chapter/ChapterFormModal.vue

@@ -0,0 +1,79 @@
+<script setup lang="ts">
+import { ref, watch, computed } from 'vue'
+import type { Chapter } from '@/types/chapter'
+import BaseModal from '@/components/ui/BaseModal.vue'
+import BaseInput from '@/components/ui/BaseInput.vue'
+import BaseButton from '@/components/ui/BaseButton.vue'
+
+const props = defineProps<{
+  show: boolean
+  chapter: Chapter | null
+  saving: boolean
+}>()
+
+const emit = defineEmits<{
+  submit: [data: { title: string }]
+  close: []
+}>()
+
+const title = ref('')
+
+const isEdit = computed(() => !!props.chapter)
+const modalTitle = computed(() => isEdit.value ? '重命名章节' : '新建章节')
+const canSubmit = computed(() => title.value.trim().length > 0 && !props.saving)
+
+watch(() => props.show, (val) => {
+  if (val) {
+    title.value = props.chapter?.title ?? ''
+  }
+})
+
+function handleSubmit() {
+  if (!canSubmit.value) return
+  emit('submit', { title: title.value.trim() })
+}
+</script>
+
+<template>
+  <BaseModal :show="show" @close="emit('close')">
+    <form class="chapter-form" @submit.prevent="handleSubmit">
+      <h2 class="form-title">{{ modalTitle }}</h2>
+
+      <BaseInput
+        v-model="title"
+        label="章节标题"
+        :maxlength="200"
+        required
+      />
+
+      <div class="form-actions">
+        <BaseButton variant="secondary" type="button" @click="emit('close')">取消</BaseButton>
+        <BaseButton variant="primary" type="submit" :loading="saving" :disabled="!canSubmit">
+          {{ isEdit ? '保存' : '创建' }}
+        </BaseButton>
+      </div>
+    </form>
+  </BaseModal>
+</template>
+
+<style scoped>
+.chapter-form {
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-lg);
+}
+
+.form-title {
+  font-family: var(--font-display);
+  font-size: 1.4rem;
+  font-weight: 700;
+  color: var(--ink-900);
+}
+
+.form-actions {
+  display: flex;
+  justify-content: flex-end;
+  gap: var(--space-sm);
+  padding-top: var(--space-sm);
+}
+</style>