Refactor Sudoku solver architecture

logic/strategies/naked.go

@@ -1,6 +1,6 @@
 package strategies
 
-import "git.kleiax.de/homepage/board"
+import "git.kleiax.de/homepage/field"
 
 // ────────────────────────────────────────────────────────────────────────────── //
 // NAKED_SINGLE STRUCTURE                                                         //
@@ -11,13 +11,13 @@ type NakedSingle struct {
 }
 
 func (ns *NakedSingle) SearchProgressableCells() int {
-	ns.field.ForEachPart(func(part board.Part) {
-		part.ForEachCell(func(cell *board.Cell) {
+	ns.field.ForEachPart(func(part field.Part) {
+		part.ForEachCell(func(cell *field.Cell) {
 			candidates := cell.Notes.Get()
 			if len(candidates) == 1 && cell.GetNumber() == 0 {
-				change := board.ExternalChange{
+				change := field.ExternalChange{
 					Cell:       cell,
-					Action:     board.ActionSetNumber,
+					Action:     field.ActionSetNumber,
 					Value:      candidates[0],
 					From:       cell.GetNumber(),
 					TriggerdBy: ns.getName(),