🎮 Add save/load game functionality

[officialerictm]

🎮 Add save/load game functionality

Overview

Implement an efficient save/load system that maintains our ultra-minimal code style while allowing players to persist their game progress.

Current State

• Game state resets on page refresh
• All progress (gems, upgrades, collections) is lost when closing the game
• State is currently managed in a single useState hook: const[s,S]=useState({g:0,p:0,n:[],c:{},u:{}})

Proposed Solution

Following our optimization principles:

// Minimal localStorage implementation
const sv=()=>localStorage.setItem('g',JSON.stringify(s))
const ld=()=>{const d=localStorage.getItem('g');if(d)S(JSON.parse(d))}

Implementation Details

1. Add auto-save on state changes
2. Load saved game on startup
3. Handle migration/versioning with minimal overhead
4. Maintain optimization patterns established in base code

Acceptance Criteria

• Game state persists across sessions
• Save/load adds <0.5kb to codebase
• No performance impact on particle system
• Maintains current state structure
• Handles missing/corrupt save data gracefully

Technical Notes

• Use existing state object structure
• Consider using useEffect for auto-save
• Potential compression for large save states
• Version tracking for future compatibility

Optimization Goals

• Keep additional code under 20 lines
• Maintain current variable naming conventions
• No additional dependencies
• Preserve current performance metrics

Questions to Consider

• Should we add a manual save button?
• How often should we auto-save?
• Do we need save slots?