fix(simulation): add TileKind to VisibleTile wire protocol (#412)

Server was sending visible_tiles without tile type data, so the client
could not distinguish floor from wall in live mode. Add TileKind enum
(Floor/Wall/Door/Object) to VisibleTile, populated from WalkabilityMap
in the NaturalVision perception query. Update test fixtures to include
the new field. Uses #[serde(default)] for backward compatibility.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/tests/gen_fixtures.rs

@@ -176,18 +176,21 @@ fn generate_msgpack_fixtures() {
                 y: 10,
                 z: 0,
                 visibility: VisibilitySector::Forward,
+                tile_kind: TileKind::Floor,
             },
             VisibleTile {
                 x: 11,
                 y: 10,
                 z: 0,
                 visibility: VisibilitySector::Peripheral,
+                tile_kind: TileKind::Floor,
             },
             VisibleTile {
                 x: 10,
                 y: 9,
                 z: 0,
                 visibility: VisibilitySector::Forward,
+                tile_kind: TileKind::Floor,
             },
         ],
         nearby_interactions: vec![],

server/tests/serialization.rs

@@ -205,12 +205,14 @@ fn snapshot_v2_fields_roundtrip() {
                 y: 10,
                 z: 0,
                 visibility: VisibilitySector::Forward,
+                tile_kind: TileKind::Floor,
             },
             VisibleTile {
                 x: 6,
                 y: 10,
                 z: 0,
                 visibility: VisibilitySector::Peripheral,
+                tile_kind: TileKind::Wall,
             },
         ],
         nearby_interactions: vec![],