feat: Implement full Orders & Evolution class tree

[madjin]

Summary

Implement the complete Orders system with progression paths from base class to mastery.

Class Tree

CONTRIBUTOR (default starting class)
│
├── Builder Order
│   └── Builder → Engineer → Architect
│
├── Hunter Order
│   └── Hunter → Tracker → Warden
│
├── Scribe Order
│   └── Scribe → Archivist → Professor
│
├── Maintainer Order (evolution from Builder)
│   └── Maintainer → Steward → Guardian
│
└── Machine Order (AI agents)
    └── Droid → Daemon → Oracle

Evolution Mechanics

• Base class unlocks at "regular" tier (score >= 50)
• Specialization unlocks at "veteran" tier (score >= 500)
• Mastery unlocks at "legend" tier (score >= 5000)

Acceptance Criteria

• Define evolution thresholds for each Order
• Implement tier-based evolution logic
• Add evolutionPath field to ScoreBreakdown
• Update API documentation with full class tree
• Consider making thresholds configurable in config/example.json

Related

• PR feat: add MMORPG-style character system to leaderboard API #193 establishes base class system (Builder, Hunter, Scribe, Maintainer, Pathfinder)