feat(demo): use beautiful-mermaid for pipeline visualization

- Add beautiful-mermaid library (single-file ASCII renderer)
- Update pipeline_viz to generate mermaid graphs and render with beautiful-mermaid
- Creates dimensional network visualization with arrows connecting nodes
- Animates through effects and highlights active camera mode

engine/app.py

@@ -572,7 +572,7 @@ def run_pipeline_demo():
         get_registry,
         set_monitor,
     )
-    from engine.pipeline_viz import generate_animated_pipeline
+    from engine.pipeline_viz import generate_network_pipeline
 
     print("  \033[1;38;5;46mMAINLINE PIPELINE DEMO\033[0m")
     print("  \033[38;5;245mInitializing...\033[0m")
@@ -667,7 +667,7 @@ def run_pipeline_demo():
 
             camera.update(config.FRAME_DT)
 
-            buf = generate_animated_pipeline(w, frame_number)
+            buf = generate_network_pipeline(w, h, frame_number)
 
             ctx = EffectContext(
                 terminal_width=w,