feat: Infinite Endless Mode — Remove Finish Line

[saucegodbased]

Infinite Endless Mode — Remove Finish Line

Replaces the current fixed-length track with a procedurally generated infinite track. The game has no ending — the player keeps going until they fall off the track.

Changes

Track Generation (track.js)

• Replaced fixed WAYPOINTS array with procedural waypoint generation using seeded RNG
• Added initTrack(seed) for initializing procedural generation
• Added ensureTrackTo(minDistance) for lazy track extension ahead of ball
• Removed FINISH_LINE_DISTANCE export
• Dynamic trackLength that grows as waypoints are added

Chunk-Based Rendering (renderer.js)

• Implemented chunk system (CHUNK_SIZE=30) for dynamic track segment generation/culling
• Track meshes, obstacles, coins, turtles, and moving walls generated per-chunk
• Old chunks behind ball are destroyed to prevent unbounded memory growth
• Removed buildFinishLine() and all finish line mesh handling
• Added updateChunks(ballDistance) called each frame from game loop
• Seeded RNG per chunk ensures deterministic obstacle/item placement

Physics (physics.js)

• Removed finish line distance check — game no longer ends at a fixed point
• Removed track length clamping on ball distance
• Game over triggered only by ball falling off track

Game Loop (main.js)

• Removed enterFinished() function and finished state handling
• Added updateChunks() call in game loop for continuous track generation
• Score/distance/timer continue incrementing indefinitely
• Level indicator and background colors cycle based on distance milestones

Server (server.js)

• Increased MAX_REASONABLE_SCORE from 10,000 to 1,000,000 for infinite mode

Acceptance Criteria

• Fixed finish line removed; no predefined end point
• Track segments procedurally generated ahead of ball position
• Obstacles spawn procedurally on new track segments
• Old track segments and objects culled behind ball
• Game-over only on falling off track
• Score/distance continues incrementing
• Level indicator and background colors function via distance milestones
• Memory managed via chunk culling for smooth 60fps performance