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/architecture.md

@@ -1,5 +1,9 @@
 # 系统架构全景
 
 <div class="mt-2 flex justify-center">
-  <img src="../public/architecture.svg" class="w-full max-h-[500px] object-contain" />
+  <img src="../public/architecture.svg" class="w-full max-h-[450px] object-contain" />
 </div>
+
+<!--
+指向架构图各层讲解：前端 → API → 管线 → 存储
+-->