This commit introduces a comprehensive tower placement system allowing players to select and place towers on valid platform tiles. Key changes include:
- Added tower selection and preview functionality with visual feedback (green for valid, red for invalid positions)
- Implemented cannon tower type with AOE damage capabilities
- Integrated next wave button with animation effects in the UI
- Modified wave progression to be controlled via interface manager instead of automatic timing
- Enhanced tower placement logic to snap to grid and validate platform collisions
- Updated gold management system with proper removal when placing towers
The changes enable players to strategically place multiple tower types while providing visual feedback during selection and integrating seamlessly with the existing wave progression system.
