Lucidly syUSD auto-park for idle agent balances

[abhicris]

Extend switchboard agent wallets so idle USDC balances automatically park into Lucidly's syUSD vault and earn yield between agent actions. Core value-add for Create Protocol Phase 2 agents.

Scope

• New module switchboard/adapters/lucidly.py wrapping the ILucidlyVault interface (spec'd in kcolbchain/stablecoin-toolkit — companion issue).
• Per-wallet config: idle_target_bps (e.g. 8000 = 80% parked / 20% liquid).
• Auto-rebalance hook: runs after every agent settlement, checks liquid buffer vs target, moves excess into vault.
• Unpark-on-demand: when agent's next tx would exceed liquid buffer, pull from vault before broadcasting.
• Yield accrual reporting per wallet.

Acceptance

• Unit tests with a mock Lucidly vault (no mainnet calls in CI).
• Config validation: can disable entirely, can cap per-wallet parked amount, can set per-chain targets (Arbitrum vs Ethereum vs Base).
• Integration test with the gas-budget tracker (feat: gas budget tracker with configurable hour/day limits (closes #5) #14 predecessor) — parking should not starve gas reserves.

Why

• Create Protocol relaunch-plan.md §Phase 1: "Lucidly syUSD vault — idle agent deposits auto-earn yield."
• Differentiator vs plain-wallet competitors — agent balances earn automatically.

Labels

enhancement, help wanted.