feat(06-01): add animation.matchDuration to CONFIG

- Add animation configuration object with matchDuration: 250ms
- Per CONTEXT.md recommendation (200-300ms range)

gsd-framework/src/config.ts

@@ -24,4 +24,7 @@ export const CONFIG = {
     selection: '#e94560',
     text: '#eaeaea',
   },
+  animation: {
+    matchDuration: 250, // ms - scale+fade duration per CONTEXT.md
+  },
 } as const;