docs(readme): add animated "path lights up" demo to See it in action

An animated SVG that mirrors the real `graphify path` output: a terminal
types the query on the left while the answer draws itself hop by hop across
the knowledge graph on the right, ending on "3 hops. Zero files opened."

Pure SMIL inside a self-contained dark card, so it renders inline on both
GitHub themes with no JS and no external fonts. Palette is brand-only:
muted emerald (sampled from the logo) as the single accent, no neon.
Generated by scripts/gen_demo_path.py (re-run to regenerate; STATIC=1 bakes
a still frame for QA).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -70,6 +70,10 @@ A knowledge graph is not a vector index: it is **deterministic**, **every edge i
 
 ## See it in action
 
+<p align="center">
+  <img src="https://raw.githubusercontent.com/Graphify-Labs/graphify/v8/docs/demo-path.svg" alt="graphify path query: a terminal asks for the shortest path between FastAPI and ModelField, and the answer lights up hop by hop across the knowledge graph" width="900">
+</p>
+
 Once the graph is built you query it instead of reading files. Real output, graphify run on the FastAPI codebase shown above:
 
 ```text