feat: expand gen2D deck with deep technical slides and interactive elements

- Add 5 new slide pages: eino-deep-dive, ratelimit-overview, ratelimit-lua, async-deep-dive, harness
- Add 4 new drawio SVGs: pipeline-detail, ratelimit, async-task, harness
- Update all existing slides with v-clicks progressive reveal
- Add presenter notes and interactive prompts
- Expand slides.md to register all new pages (16 → 25+ slides)
- Fix text overflow by trimming content per Item block
- Add Eino Graph deep dive: WithGenLocalState, Pre/Post Handler, branch routing
- Add rate limiting section: algorithm comparison, Lua script, Gin middleware
- Add async task deep dive: TaskQueue FIFO, context progress injection
- Add consistency section: style/pipeline/data/deployment 4-layer guarantees

decks/gen2D/pages/async-task.md

@@ -2,6 +2,8 @@
 
 提交即返回，后台并发执行
 
+<v-clicks>
+
 <Item title="📤 任务提交 → 后台执行">
 
 1. 提交请求 → 创建 Task（`running`）→ 立即返回 `taskId`
@@ -22,3 +24,5 @@
 质检重试最多 3 次，任务级重试 1 次，超限降级输出。
 
 </Item>
+
+</v-clicks>