- Add PALETTES object with MAGENTA, CYAN, LIME, WHITE presets
- Add PALETTE_KEYS array for palette cycling
- Change gameState initial value from 'modeSelect' to 'title'
- Add activePalette, soundEnabled, selectedMenu, previousState to GameState
- Initialize GameState.activePalette to MAGENTA preset after GameConfig is defined
- Added mode/difficulty/restart key handlers to Input._handleKeyDown
- Rewrote GameLoop.main() with full state machine (modeSelect, diffSelect, playing, scored, gameover)
- Added score detection in GameLoop (ball exits left/right edge)
- Added 1s pause after score then auto-serve
- Added match-end check (first to 7 wins) with winner overlay
- Added center divider line and real-time score display
- Renders both paddles during gameplay
- Removed Physics out-of-bounds auto-serve (GameLoop now owns scoring)
- Removed Phase 1 debug speed display
- Added pauseTime field to GameLoop
- Add AI object with init(), update(), _predictBallY() methods
- AI uses predictive ray-cast with wall bounce simulation to intercept ball
- AI respects difficulty config (speed, reactionDelay, errorMargin) from GameConfig
- Add Physics._checkPaddle2Collision() with 5-zone deflection, ball goes LEFT
- Extend Physics.update() with paddle2 movement branch (2p/ai modes)
- Add AI.init() to initialization block
- Add WIN_SCORE, AI_EASY, AI_MEDIUM, AI_HARD to GameConfig
- Add paddle2, score1, score2, mode, difficulty, gameState, winner to GameState
- Replace anonymous Input handlers with named refs + cleanup() method
- Add Input.getVerticalInput2() for ArrowUp/ArrowDown keys
- Position paddle2 on right side in Physics.init()
- Update Physics.onResize() to call init() for full repositioning
- Add GameConfig with initialBallSpeed (220px/s), speedIncrement (18px/s), paddleSpeed (400px/s)
- Add Physics.serveBall(): centers ball, sets random angle (-45 to +45 deg), random left/right dir
- Replace Physics.update() skeleton with full ball movement and wall bounce logic
- Add Physics._checkPaddleCollision() with 5-zone angle deflection and speed increment per hit
- Ball exits left/right bounds → immediate re-serve from center
- Ball pushed out of paddle on collision to prevent double-hit next frame
- Add on-canvas speed debug display (Phase 1 verification aid)
- Created index.html with valid HTML5 structure and black full-window canvas
- Renderer object with devicePixelRatio-aware resize() using logical vs bitmap coords
- CSS enforces overflow:hidden with no scrollbars
- Minimum 4:3 aspect ratio enforcement in resize logic
- window.addEventListener('resize') handler for live canvas rescaling
