feat(player): animate authoritative hedge breakthroughs

docs/UI_STYLE.md

@@ -130,9 +130,13 @@ are not MVP requirements.
 - Server-approved breakthrough impacts one through four bend the visible bush
   wall with four increasing restrained stages and no text or spike notice. A
   fifth accepted move is reflected by a permanent textured trampled-bush gap.
-  The browser uses one restartable impact timer and no generated particles.
+  Only a received opened-edge projection paired with an adjacent authoritative
+  player position may start one 480 ms hedge-parting, player dash, and fixed
+  four-accent leaf-and-sparkle sequence. It uses one restartable timer and no
+  unbounded generated particles.
   `rate_limited` still darkens and blurs only the maze for at most 520 ms.
-- Reduced-motion mode uses static deformation and the same trampled-gap state.
+- Reduced-motion mode uses static deformation and the same trampled-gap state;
+  it never shows travel or moving accents.
 
 ### Hedge art review contract
 
@@ -152,8 +156,9 @@ are not MVP requirements.
 - Impact stages one through four retain the same wall centre while increasingly
   compressing foliage, bending twigs, and shedding a fixed small number of
   leaves. The breakthrough and trampled symbols leave a clear centred passage
-  at least 16 CSS pixels wide at 40-pixel scale, with flattened vegetation on
-  both sides. They never imply movement beyond that one authoritative edge.
+  at least 24 CSS pixels wide at 40-pixel scale, with two separated foliage
+  clusters, bent branches, and restrained ground debris on both sides. They
+  never imply movement beyond that one authoritative edge.
 - Review sheets show the source symbols on neutral and dark-cell backgrounds
   at 34, 40, and 46 CSS pixels. They contain no coordinates, objects,
   ownership, hidden topology, animation, or runtime dependencies.
@@ -185,7 +190,11 @@ are not MVP requirements.
   objects and players, and may overhang an edge by at most 15% of a cell. A
   projection replacement removes all obsolete edge nodes. One restartable
   breakthrough timer may briefly show the approved breakthrough frame; reduced
-  motion settles immediately on the permanent breach.
+  motion settles immediately on the permanent breach. A player-only transient
+  runner replaces the focal avatar for at most 480 ms after a matching opened
+  edge and adjacent authoritative move; it has exactly four non-interactive
+  accents and is cleared on any newer projection, pause, disconnect, result,
+  reset, screen change, or reduced-motion mode.
 
 ## 8. Responsive behavior