Labels in normal orientation (not X-mirrored)

User wanted the image to be X-mirrored (NS-mirror, so place
names on a map are correctly mirrored for the corridor
orientation), but the text labels to be readable normally.

Now labels are drawn in normal orientation:
- N at top-left
- S at bottom-left
- y at top-right
- x at bottom-right

The text is no longer reversed. With the corridor's X-swap
arrangement, this means:
- screen left = west tiles (low x)
- screen right = east tiles (high x)
- within each tile, the image is X-mirrored, but the text
  inside is readable

vendor/clouds3d.js

@@ -370,29 +370,27 @@ function drawTileAt(lng, perp, dx, dz, centerTileX, centerTileY) {
         groundCtx.strokeStyle = 'rgba(0,0,0,0.85)';
         groundCtx.lineWidth = 3;
         groundCtx.font = 'bold 40px sans-serif';
-        // Helper: draw a horizontally-mirrored label at (x, y).
-        function mirrorLabel(text, x, y, align) {
-            groundCtx.save();
-            groundCtx.translate(x, y);
-            groundCtx.scale(-1, 1);
-            groundCtx.textAlign = align;
-            groundCtx.strokeText(text, 0, 0);
-            groundCtx.fillText(text, 0, 0);
-            groundCtx.restore();
-        }
-        // S at top-left, textAlign 'right' so the text's right edge
-        // is at the anchor (text extends into the tile from the left
-        // edge of the tile area).
-        mirrorLabel('S', canvasX + 12, canvasY + 44, 'right');
-        // N at bottom-left
-        mirrorLabel('N', canvasX + 12, canvasY + 244, 'right');
-        // Tile coordinates, top-right and bottom-right corners
+        // Labels in normal (non-mirrored) orientation so the user can
+        // read them. The image content itself is X-flipped (NS-mirror)
+        // for the corridor orientation; the labels are drawn on top
+        // in normal orientation for legibility.
+        groundCtx.font = 'bold 40px sans-serif';
+        groundCtx.textAlign = 'left';
+        // N at top-left of tile area (image north is at canvas top)
+        groundCtx.strokeText('N', canvasX + 12, canvasY + 44);
+        groundCtx.fillText('N', canvasX + 12, canvasY + 44);
+        // S at bottom-left
+        groundCtx.strokeText('S', canvasX + 12, canvasY + 244);
+        groundCtx.fillText('S', canvasX + 12, canvasY + 244);
+        // Tile coordinates
         groundCtx.font = 'bold 18px monospace';
-        // y at top-right, textAlign 'left' so text extends into the
-        // tile from the right edge.
-        mirrorLabel('y=' + tileY, canvasX + GROUND_TILE_SIZE - 12, canvasY + 28, 'left');
+        groundCtx.textAlign = 'right';
+        // y at top-right
+        groundCtx.strokeText('y=' + tileY, canvasX + GROUND_TILE_SIZE - 12, canvasY + 28);
+        groundCtx.fillText('y=' + tileY, canvasX + GROUND_TILE_SIZE - 12, canvasY + 28);
         // x at bottom-right
-        mirrorLabel('x=' + tileX, canvasX + GROUND_TILE_SIZE - 12, canvasY + GROUND_TILE_SIZE - 12, 'left');
+        groundCtx.strokeText('x=' + tileX, canvasX + GROUND_TILE_SIZE - 12, canvasY + GROUND_TILE_SIZE - 12);
+        groundCtx.fillText('x=' + tileX, canvasX + GROUND_TILE_SIZE - 12, canvasY + GROUND_TILE_SIZE - 12);
 
         return true;
     }).catch(function() {