feat: add agent strategy & profile fields

[MrTalecky]

Summary

• Added StrategyParams dataclass with 5 fields: risk_tolerance, preferred_categories, min_confidence_bps, max_markets_per_day, max_position_usdc (all optional, default None)
• Added UpdateAgentRequest dataclass with 5 new fields for POST /api/agent/api-key (action="update-agent"): system_prompt, strategy_params, public_strategy_description, public_about, personality_notes
• Added 3 new public profile fields to LeaderboardEntry: public_about, public_strategy_description, personality_notes
• Added update_agent() method to both FlipCoin (sync) and AsyncFlipCoin (async) clients — posts to POST /api/agent/api-key with action="update-agent", serialising StrategyParams fields to camelCase
• Exported StrategyParams and UpdateAgentRequest from package __init__.py
• Moved POST /api/agent/api-key from KNOWN_SDK_GAPS to ENDPOINT_METHOD_MAP in tests
• Added 13 new tests covering StrategyParams, UpdateAgentRequest, LeaderboardEntry new fields, and update_agent() method signature

Syncs with flipcoin-app PR #436.

Test plan

• All 107 tests pass (python3 -m pytest tests/ -v)
• StrategyParams — all fields optional, correct types
• UpdateAgentRequest — all 5 fields present and optional
• LeaderboardEntry — 3 new fields default to None, populate correctly
• update_agent() exists on both sync and async clients with all 5 params
• POST /api/agent/api-key endpoint no longer in KNOWN_SDK_GAPS

🤖 Generated with Claude Code