added Type Jam puzzle app for review (#1554)

* added Type Jam puzzle app for review

* pr round 2 prep

* updated ci scripts for varfont_shader_puzzle

* resolved unused and minor variable naming issues

* rotator tiles row and col are final vars now

* removed unused import and print from production

* made constructors const where needed

* pages_flow export refactored to directly come from that file

* removed old api commented out section from FragmentShaded

* updated pubspec yaml to correct project name

* dart min version updated; removed unnecessary commented out dependencies from pubspec.yaml

* updated pubspec.yaml min flutter version to ensure FragmentShader support

* added/edited comments for explanation, esp on var fonts; removed obsolete comments

* trailing newline added to pubspec.yaml eof

experimental/varfont_shader_puzzle/lib/model/puzzle_model.dart

@@ -0,0 +1,50 @@
+// Copyright 2023 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+class PuzzleModel {
+  final int dim; // num tiles in any one dir; dim x dim board
+
+  // 2d array like a board
+  // x is the tileID and its position in the array mirrors the board
+  List<List<int>> positions = [<int>[]];
+
+  // rotation states, where index == tileID
+  // x is num of CCW rotations off from correct (x % 4 == 0 indicates correct)
+  List<int> status = [];
+
+  PuzzleModel({required this.dim}) {
+    for (int i = 0; i < dim; i++) {
+      if (positions[positions.length - 1].length == dim) {
+        positions.add(<int>[]);
+      }
+      positions[positions.length - 1].add(i);
+      status.add(0);
+    }
+  }
+
+  bool allRotationsCorrect() {
+    for (int i = 0; i < status.length; i++) {
+      if (status[i] % 4 != 0) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  void setTileStatus(int tileID, int newStatus) {
+    status[tileID] = newStatus;
+  }
+
+  int getTileStatus(int tileID) {
+    return status[tileID];
+  }
+
+  void rotateTile(int tileID) {
+    status[tileID]--;
+  }
+
+  int getRotationOfTile(int tileID) {
+    return status[tileID];
+  }
+}