M7.4a: PlayScreen polish — facing tick, road overlap, WASD pan

Facing tick stuck at the initial angle. PlayerMarker._Draw was
computing the tick direction from a FacingAngleRad auto-property,
but Godot caches CanvasItem draw commands and only re-runs _Draw on
QueueRedraw. Setter never called QueueRedraw → tick never rotated.
Fixed by leaning on the Node2D transform instead: tick is drawn
along the local +X axis, PlayScreen sets marker.Rotation = facing
each frame. The transform rotation applies to the cached commands
without re-invoking _Draw — efficient and correct. FacingAngleRad
property removed; ShowFacingTick became a property with QueueRedraw
on change (visibility toggle still needs to invalidate the cache).

Tactical view double-drew roads. TacticalChunkGen.Pass2_Polylines
already bakes roads + rivers + bridges into the surface tiles of
each chunk. WorldRenderNode's Line2D overlay was still visible at
tactical zoom, stroking the same path on top of the rasterised
version — showed as a brown line over every road. Ported the
MonoGame "suppress polyline overlay in tactical" rule into
UpdateLayerVisibility: _polylineLayer and _bridgeLayer hide when
zoom >= TacticalRenderZoomMin.

WASD now pans the world map. Previously WASD did nothing in
world-map mode — only right-drag / middle-drag / mouse-wheel worked.
WASD is now context-sensitive: tactical mode steps the player
(unchanged), world-map mode pans the camera at 400 screen px/sec
(world-pixel speed scales as 1/zoom so the perceived rate stays
constant). Diagonal motion is √2-normalised to match tactical step.
Suppressed during click-to-travel since the camera-follow would
clobber any pan input anyway. HUD hint updated.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Theriapolis.Godot/Rendering/WorldRenderNode.cs

@@ -288,10 +288,22 @@ public partial class WorldRenderNode : Node2D
     {
         if (_camera is null) return;
         float zoom = _camera.Zoom.X;
+        bool tactical = zoom >= TacticalRenderZoomMin;
+
         if (_tacticalLayer is not null)
-            _tacticalLayer.Visible = zoom >= TacticalRenderZoomMin;
+            _tacticalLayer.Visible = tactical;
         if (_settlementLayer is not null)
             _settlementLayer.Visible = zoom < SettlementHideZoom;
+
+        // Polylines and bridges are baked into the tactical chunk surface
+        // tiles by TacticalChunkGen.Pass2_Polylines, so re-stroking the
+        // Line2D overlay at tactical zoom double-draws the road and shows
+        // as a brown line over top of the rasterised one. Hide the line
+        // overlay when tactical is active.
+        if (_polylineLayer is not null)
+            _polylineLayer.Visible = !tactical;
+        if (_bridgeLayer is not null)
+            _bridgeLayer.Visible = !tactical;
     }
 
     private void UpdateZoomScaledNodes()