Start writing the web app

Signed-off-by: Nikolai Rodionov <allanger@posteo.com>

lib/features/authorization/presentation/decoration.dart

@@ -0,0 +1,89 @@
+import 'dart:math' as math;
+import 'package:flutter/material.dart';
+import 'package:softplayer_web/shared/ui/colors/light_mode.dart';
+
+class AuthDecoration extends StatelessWidget {
+  final double spacing;
+  final Color color;
+
+  const AuthDecoration({
+    super.key,
+    this.spacing = 24,
+    this.color = Colors.blue,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        return Container(
+          color: LightModeColors.backgroundElevated,
+          child: FractionallySizedBox(
+            widthFactor: 0.3,
+            alignment: Alignment.centerLeft,
+            child: CustomPaint(
+              painter: _GridPainter(spacing: spacing, color: color),
+              child: const SizedBox.expand(),
+            ),
+          ),
+        );
+      },
+    );
+  }
+}
+
+// todo: Some AI generated shite, that doesn't work
+class _GridPainter extends CustomPainter {
+  final double spacing;
+  final Color color;
+
+  _GridPainter({required this.spacing, required this.color});
+
+  static const double maxSquare = 85;
+  static const double minSquare = 48; // 2x gap
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final paint = Paint()..color = color;
+
+    // ✅ outer padding included in layout math
+    final innerWidth = size.width - spacing * 2;
+    final innerHeight = size.height - spacing * 2;
+
+    int columns = 10;
+
+    double calcSize(int cols) {
+      return (innerWidth - (cols - 1) * spacing) / cols;
+    }
+
+    // choose columns safely
+    while (columns > 1 && calcSize(columns) < minSquare) {
+      columns--;
+    }
+
+    double square = calcSize(columns);
+    square = math.min(square, maxSquare);
+
+    final rows = (innerHeight / (square + spacing)).ceil();
+
+    for (int row = 0; row < rows; row++) {
+      final y = spacing + row * (square + spacing);
+
+      for (int col = 0; col < columns; col++) {
+        final x = spacing + col * (square + spacing);
+
+        final rect = Rect.fromLTWH(x, y, square, square);
+
+        canvas.drawRRect(
+          RRect.fromRectAndRadius(rect, const Radius.circular(6)),
+          paint,
+        );
+      }
+    }
+  }
+
+  @override
+  bool shouldRepaint(covariant _GridPainter oldDelegate) {
+    return oldDelegate.spacing != spacing || oldDelegate.color != color;
+  }
+}