style: optimize gen2D deck layout, animations, and visual hierarchy

- style-keys.md: add v-clicks to 3x2 grid for staggered animation
- eino-graph.md: two-column layout (code left, Items right)
- eino-deep-dive.md: two-column layout for both slides, code+Items side-by-side
- async-deep-dive.md: two-column layout for both slides, SVG integrated
- harness.md: two-column layout for slide 1 (code left, Items right)
- request-journey.md: two-column layout for journey steps
- data-model.md: add v-clicks to grid items, increase diagram height
- architecture/pipeline/prompt-agent: increase SVG max-height for better visibility

decks/gen2D/pages/eino-graph.md

@@ -1,6 +1,8 @@
 # Eino 管线编排 — compose.Graph
 
-<div class="mt-2">
+<div class="grid grid-cols-2 gap-4 mt-2">
+
+<div>
 
 ```go {all|1-4|6-10|all}
 type PipelineInput struct {
@@ -22,6 +24,8 @@ type PipelineOutput struct {
 
 </div>
 
+<div class="flex flex-col justify-center">
+
 <v-clicks>
 
 <Item title="graph.Build() — 构建管线">
@@ -33,3 +37,7 @@ type PipelineOutput struct {
 </Item>
 
 </v-clicks>
+
+</div>
+
+</div>