feat(yvusd): add yvUSD vault monitoring

[spalen0]

Summary

• Add monitoring script for yvUSD vault (closes Yvusd monitoring #193)
• APY anomaly detection: alerts when unlocked APY > locked APY for >6 hours (incentive misalignment), and when any strategy has negative APR
• CCTP bridging delays: checks cross-chain strategy lastReport timestamps, alerts if stale (>48h)
• Flashloan liquidity: checks Morpho borrow positions vs available liquidity (Balancer vault + Morpho market) for looper strategy unwinding
• Large cooldown requests: scans CooldownStarted events on LockedyvUSD, alerts on >$100K requests

Strategy discovery

Looper and cross-chain strategies are discovered dynamically from the yvUSD APR API, so no hardcoded strategy list to maintain.

Contract ABIs

Minimal ABIs for:

• Yearn V3 Vault (strategies(), totalAssets())
• Morpho Blue (market(), position())
• LockedyvUSD (CooldownStarted event, getCooldownStatus(), totalSupply())

Test plan

• Verify API fetch works against yvusd-api.yearn.fi/api/aprs
• Verify on-chain calls succeed with a mainnet RPC
• Test cache persistence for APY inversion tracking
• Confirm CooldownStarted event signature matches LockedyvUSD contract
• Add to hourly GitHub Actions workflow

🤖 Generated with Claude Code