feat(agent): 添加视频创作工作流技能系统和流程工具

新增基于 SKILL.md 的视频创作工作流系统，Agent 可通过 skills 目录加载结构化的导演指令；实现 validate_storyboard、update_manifest_items、confirm_images 三个流程工具支撑分镜校验、提示词更新和图片确认。

web/server/agent/tools/confirm-images.ts

@@ -0,0 +1,26 @@
+import { execSync } from 'child_process';
+import { PIPELINE_SCRIPT, PROJECT_ROOT } from './shared';
+import type { ToolDefinition } from './types';
+
+export const confirmImages: ToolDefinition = {
+  name: 'confirm_images',
+  description: '确认分镜图质量，将 manifest 中所有图片标记为 confirmed=true。也可以跳过确认直接批量确认。',
+  input_schema: {
+    type: 'object',
+    properties: {
+      manifestPath: { type: 'string', description: 'manifest.json 路径' },
+      skip: { type: 'boolean', description: '跳过人工确认，直接全部确认（默认 false）' },
+    },
+    required: ['manifestPath'],
+  },
+  execute: async (params) => {
+    const { manifestPath, skip = false } = params as { manifestPath: string; skip?: boolean };
+    try {
+      const cmd = `node "${PIPELINE_SCRIPT}" confirm --manifest "${manifestPath}"${skip ? ' --all' : ''}`;
+      const output = execSync(cmd, { cwd: PROJECT_ROOT, encoding: 'utf-8' });
+      return `图片确认完成:\n${output}`;
+    } catch (err: any) {
+      return `确认失败: ${err.message}`;
+    }
+  },
+};