feat(trails): render authoritative player route trails

docs/PLAYER_UI.md

@@ -94,6 +94,10 @@ received cells. It hashes each visible edge deterministically to choose the
 approved local SVG variant, so the browser neither retains unseen geometry nor
 decides topology. The layer is decorative and cannot receive input.
 
+Each complete projection also replaces one bounded SVG trail layer. It draws
+only server-authorized visible east/south passage masks: yellow and blue use
+different dotted rhythms, and a shared passage retains both patterns.
+
 All remaining Russian system messages use one `role=status` live message rail
 above the application top bar. One connection-loss message has highest priority
 and remains until a successful recovery; other messages deduplicate, replace

docs/PROTOCOL.md

@@ -56,7 +56,9 @@ is only echoed for correlation; it grants no authority.
 - `active`: the exact authoritative activation instant.
 - `view`: a bounded chunk of a role-specific authoritative game projection.
   Observer chunks contain the complete maze and both player records, including
-  their connection state; player chunks retain the fog-of-war boundary.
+  their connection state; player chunks retain the fog-of-war boundary. Each
+  projected cell carries compact Player 1 and Player 2 trail ownership masks
+  for its east and south edges only when both edge endpoints are authorized.
 - `pause`: identifies the disconnected player slot and its monotonic reconnect
   deadline.
 - `resume`: reports that both players are attached and authoritative gameplay

docs/UI_STYLE.md

@@ -110,6 +110,9 @@ are not MVP requirements.
   It opens a confirmation modal; a player match, including a finished result,
   warns that it returns everyone to the waiting lobby, while observer and
   waiting-lobby departures explain that only this browser's place is released.
+- Trails are dotted passage-center lines beneath maze objects and hedges: Player
+  1 uses the established yellow dot rhythm, Player 2 uses a distinct blue
+  rhythm, and shared passages draw both rhythms on one centerline.
 - A compact response indicator between the connection state and gear shows a
   rounded total response time or an explicit unknown, stale, or offline state.
   Its accessible description and settings details expose `Отклик`, `Связь`,