playing-field: always mirror for convenience

even if a field is not mirrored and only cyan is shown, teams may want
to use magenta.

src/components/spectator/PlayingField.vue

@@ -1,4 +1,5 @@
-// TEMPLATE --------------------------------------------------------------------
+s// TEMPLATE
+--------------------------------------------------------------------
 <template>
   <Modal v-if="showPopup" title="Welcome" icon="fa-face-smile" ref="modal">
     <ConfirmSetMachinePosePopup @update:isConfirmed="handleConfirmation" />
@@ -41,7 +42,7 @@
           <template v-for="hIndex in horizontalFieldSize">
             <PlayingFieldSquare
               :zone="getZoneNameFor(hIndex, verticalFieldSize - vIndex + 1)"
-              :with-dot="vIndex != 1 && (isFieldMirrored || hIndex != 1)"
+              :with-dot="vIndex != 1 && hIndex != 1"
               :isSelected="
                 selectedSquare?.zone ===
                 getZoneNameFor(hIndex, verticalFieldSize - vIndex + 1)
@@ -122,16 +123,12 @@ const showPopup = ref(false)
 // zones - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 function getZoneNameFor(x: number, y: number): string {
   let zone = ''
-  if (isFieldMirrored.value) {
-    if (x < 0) {
-      zone += 'M_'
-    } else if (x > 0) {
-      zone += 'C_'
-    } else {
-      throw new Error('x coordinate of a field can not be zero')
-    }
-  } else {
+  if (x < 0) {
+    zone += 'M_'
+  } else if (x > 0) {
     zone += 'C_'
+  } else {
+    throw new Error('x coordinate of a field can not be zero')
   }
   zone += 'Z'
   zone += Math.abs(x).toString()

src/store/fieldStore.ts

@@ -39,10 +39,8 @@ export const useFieldStore = defineStore('fieldStore', () => {
   )
 
   // -> full horizontal field size (in number of squares)
-  const fullHorizontalFieldSize: ComputedRef<number> = computed(() =>
-    isFieldMirrored.value
-      ? horizontalFieldSize.value * 2
-      : horizontalFieldSize.value,
+  const fullHorizontalFieldSize: ComputedRef<number> = computed(
+    () => horizontalFieldSize.value * 2,
   )
 
   // -> number of pixels of the horiontal or vertical diameter of a square
@@ -73,9 +71,7 @@ export const useFieldStore = defineStore('fieldStore', () => {
             squareDiameterPixels.value / 2 -
             (parseInt(zoneArr[4]) - 1) * squareDiameterPixels.value,
         ]
-        if (isFieldMirrored.value) {
-          pos[0] += fieldWidthPixels.value / 2
-        }
+        pos[0] += fieldWidthPixels.value / 2
         if (zoneArr[0] == 'M') {
           pos[0] -= parseInt(zoneArr[3]) * squareDiameterPixels.value
         } else if (zoneArr[0] == 'C') {