feat(walk): the stride is captured — walking shot 8, traversal check closed

Shot 8 shows the body mid-stride in profile: legs apart, arms counter-swinging. The
traversal release check for 0.2.0 is closed with that evidence.

The reason earlier attempts froze on one pose was not the clip. A probe of the
single-node instance showed the clip advancing normally (assetTime 0.19 -> 1.03,
rate 1.0, playing) while the pawn's speed stayed 0 and the clip stayed Idle: the
call that enables walking sat in the shot sequencer's BeginPlay, which runs before
the player pawn exists, so the cast found nothing and silently did nothing. Moved
into the per-frame follow update, the same run logs walk=1 speed=28 clip=GigLine_Walk
and the stride appears.

Also: the walk expectation was missing from visual_targets.json after the earlier
retirement, so --verify was checking 7 shots while 8 were captured. Restored; 8/8
verify.

Tools/visual_targets.json

@@ -84,6 +84,18 @@
         "Art/reference/hollywood/el-capitan-facade-day-wikimedia-2009-10-27.jpg"
       ],
       "expect": "Front view of the player body from the road: both arms hanging at the sides, hands down by the hips, face and chest visible, hero facade behind the camera"
+    },
+    {
+      "name": "demo-third-person-walk",
+      "shot": "Screenshots/demo/review-demo-third-person-walk.png",
+      "size": [
+        1920,
+        1080
+      ],
+      "references": [
+        "Art/reference/hollywood/el-capitan-facade-day-wikimedia-2009-10-27.jpg"
+      ],
+      "expect": "The player body mid-stride in profile: legs apart, arms counter-swinging, walking along the sidewalk"
     }
   ]
 }