feat: Complete 2D Visual Overhaul - Isometric to Flat Top-Down

- NEW: Flat2DTerrainSystem.js (375 lines)
- NEW: map2d_data.js procedural map (221 lines)
- MODIFIED: GameScene async create, 2D terrain integration
- MODIFIED: Player.js flat 2D positioning
- MODIFIED: game.js disabled pixelArt for smooth rendering
- FIXED: 15+ bugs (updateCulling, isometric conversions, grid lines)
- ADDED: Phase 28 to TASKS.md
- DOCS: DNEVNIK.md session summary

Result: Working flat 2D game with Stardew Valley style!
Time: 5.5 hours

src/scenes/PreloadScene.js

@@ -22,6 +22,9 @@ class PreloadScene extends Phaser.Scene {
         this.load.image('wheat_sprite', 'assets/wheat_sprite.png');
         this.load.image('stone_texture', 'assets/stone_texture.png');
 
+        // 💧 WEATHER EFFECTS
+        this.load.image('luza_sprite', 'assets/sprites/luza.png'); // Puddle sprite
+
         // New asset packs
         this.load.image('objects_pack', 'assets/objects_pack.png');
         this.load.image('walls_pack', 'assets/walls_pack.png');