feat(pipeline): implement Pipeline DSL system for automated workflows

Add complete Pipeline DSL system including:
- Rust backend (zclaw-pipeline crate) with parser, executor, and state management
- Frontend components: PipelinesPanel, PipelineResultPreview, ClassroomPreviewer
- Pipeline recommender for Agent conversation integration
- 5 pipeline templates: education, marketing, legal, research, productivity
- Documentation for Pipeline DSL architecture

Pipeline DSL enables declarative workflow definitions with:
- YAML-based configuration
- Expression resolution (${inputs.topic}, ${steps.step1.output})
- LLM integration, parallel execution, file export
- Agent smart recommendations in conversations

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

pipelines/education/classroom.yaml

@@ -0,0 +1,195 @@
+# ZCLAW Pipeline - Classroom Generator
+# 互动课堂生成器：输入课题，自动生成完整互动课堂内容
+
+apiVersion: zclaw/v1
+kind: Pipeline
+metadata:
+  name: classroom-generator
+  displayName: 互动课堂生成器
+  category: education
+  description: 输入课题，自动生成结构化大纲、互动场景和课后测验
+  tags:
+    - 教育
+    - 课件
+    - 自动生成
+  icon: 📚
+  author: ZCLAW
+  version: 1.0.0
+
+spec:
+  # 输入参数定义
+  inputs:
+    - name: topic
+      type: string
+      required: true
+      label: 课题名称
+      placeholder: 例如：牛顿第二定律
+      validation:
+        min_length: 2
+        max_length: 100
+
+    - name: difficulty
+      type: select
+      required: false
+      label: 难度等级
+      default: 中级
+      options:
+        - 初级
+        - 中级
+        - 高级
+
+    - name: scene_count
+      type: number
+      required: false
+      label: 场景数量
+      default: 5
+      validation:
+        min: 1
+        max: 20
+
+    - name: export_formats
+      type: multi-select
+      required: false
+      label: 导出格式
+      default: [html]
+      options:
+        - html
+        - markdown
+        - json
+
+  # 执行步骤
+  steps:
+    # Step 1: 解析课题，生成大纲
+    - id: generate_outline
+      description: 分析课题并生成课程大纲
+      action:
+        type: llm_generate
+        template: |
+          你是一位专业的教育内容设计师。请为以下课题设计一个结构化的课程大纲。
+
+          课题: {{topic}}
+          难度: {{difficulty}}
+          场景数量: {{scene_count}}
+
+          请生成一个 JSON 格式的大纲，包含以下结构：
+          {
+            "title": "课程标题",
+            "description": "课程简介",
+            "outline": {
+              "items": [
+                {"title": "章节1标题", "description": "章节1描述"},
+                {"title": "章节2标题", "description": "章节2描述"}
+              ]
+            }
+          }
+        input:
+          topic: ${inputs.topic}
+          difficulty: ${inputs.difficulty}
+          scene_count: ${inputs.scene_count}
+        json_mode: true
+        temperature: 0.7
+        max_tokens: 2000
+
+    # Step 2: 并行生成场景
+    - id: generate_scenes
+      description: 为每个大纲章节生成互动场景
+      action:
+        type: parallel
+        each: ${steps.generate_outline.output.outline.items}
+        max_workers: 4
+        step:
+          id: scene_item
+          action:
+            type: llm_generate
+            template: |
+              为以下课程章节生成一个互动教学场景：
+
+              课题: ${inputs.topic}
+              章节: {{item.title}}
+              章节描述: {{item.description}}
+              难度: ${inputs.difficulty}
+
+              生成 JSON 格式的场景内容：
+              {
+                "title": "场景标题",
+                "content": "场景内容描述",
+                "interaction": {
+                  "type": "quiz|discussion|demonstration",
+                  "prompt": "互动提示",
+                  "options": ["选项1", "选项2"] (如果是 quiz)
+                },
+                "key_points": ["要点1", "要点2", "要点3"]
+              }
+            input:
+              item: ${item}
+              index: ${index}
+            json_mode: true
+            temperature: 0.8
+            max_tokens: 1500
+
+    # Step 3: 生成课后测验
+    - id: generate_quiz
+      description: 根据场景内容生成测验题
+      action:
+        type: llm_generate
+        template: |
+          基于以下课程场景生成一套课后测验：
+
+          课题: ${inputs.topic}
+          场景数量: ${steps.generate_scenes.output | length}
+
+          生成 5 道选择题的 JSON 格式测验：
+          {
+            "questions": [
+              {
+                "question": "问题内容",
+                "options": ["A选项", "B选项", "C选项", "D选项"],
+                "correct": 0,
+                "explanation": "答案解释"
+              }
+            ]
+          }
+        input:
+          topic: ${inputs.topic}
+          scene_count: ${steps.generate_scenes.output | length}
+        json_mode: true
+        temperature: 0.6
+        max_tokens: 2000
+
+    # Step 4: 渲染课堂数据
+    - id: render_classroom
+      description: 组装完整的课堂数据结构
+      action:
+        type: classroom_render
+        input: |
+          {
+            "title": ${steps.generate_outline.output.title},
+            "description": ${steps.generate_outline.output.description},
+            "outline": ${steps.generate_outline.output.outline},
+            "scenes": ${steps.generate_scenes.output},
+            "quiz": ${steps.generate_quiz.output}
+          }
+
+    # Step 5: 导出文件
+    - id: export_files
+      description: 导出指定格式的文件
+      action:
+        type: file_export
+        formats: ${inputs.export_formats}
+        input: ${steps.render_classroom.output}
+
+  # 输出映射
+  outputs:
+    classroom_id: ${steps.render_classroom.output.id}
+    title: ${steps.render_classroom.output.title}
+    preview_url: ${steps.render_classroom.output.preview_url}
+    export_files: ${steps.export_files.output}
+
+  # 错误处理
+  on_error: stop
+
+  # 超时设置
+  timeout_secs: 300
+
+  # 并行工作线程上限
+  max_workers: 4