feat(simulation): add debug console server and LOS boundary wall margin

Debug and LOS tracks for Sprint 23 (#580, #584):

- DebugCommandKind enum with 10 variants (AdvanceTicks,
  SkipToContamination, TeleportToPosition, ForceContaminationActivate,
  InspectNpc, ListTriangles, ListPopulation, GetContaminationStatus,
  TeleportToLocation, ForceTriangleActivation)
- DebugResponsePayload on ObserverSnapshot, handle_debug_commands
  system gated by DebugEnabled resource
- PROTOCOL_VERSION bumped 17 → 18
- VisibilitySector::BoundaryWall variant — 1-tile wall margin beyond
  LOS boundary included in visible_tiles (not exploration/memory)
- compute_boundary_walls() pass in NaturalVision after FOV+cone

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

server/src/bridge/mod.rs

@@ -6,6 +6,7 @@ use bevy_app::prelude::*;
 use bevy_ecs::prelude::*;
 use bevy_ecs::schedule::IntoScheduleConfigs;
 
+pub mod debug;
 pub mod framing;
 pub mod local;
 pub mod tcp;
@@ -221,12 +222,17 @@ impl Plugin for BridgePlugin {
             .init_resource::<ServerRunning>()
             .init_resource::<HandshakeState>()
             .init_resource::<SimErrorBuffer>()
+            .init_resource::<debug::DebugCommandBuffer>()
+            .init_resource::<DebugEnabled>()
             .init_resource::<crate::perception::query::VisibilityGeometry>()
             .init_resource::<crate::perception::query::ActivePerceptionMode>()
             .add_systems(
                 Update,
                 (
                     receive_bridge_inputs.before(crate::simulation::input::process_player_input),
+                    debug::handle_debug_commands
+                        .after(crate::simulation::input::process_player_input)
+                        .before(crate::perception::observer::compute_observer_snapshot),
                     crate::perception::observer::compute_visibility_geometry
                         .after(crate::simulation::movement::validate_movement),
                     crate::simulation::interaction::compute_nearby_interactions