test(adapter): add hostile-callback adversarial test suite

[ericbsantana]

Description

• Add MonadVRFAdapter.adversarial.t.sol with focused tests for hostile callbacks: reverter, OOG, re-entrant, requester underpayment
• Add MockReentrant to MockConsumer.sol (existing reentrancy test attacks via fulfiller receive(), a different vector)
• No shipped contract code changed
• Full forge test 38/38 pass

Checklist

• Code compiles (pnpm build and forge build both pass)
• All tests pass (pnpm test and forge test)
• Added tests that fail without the change (where applicable; required for bug fixes)
• Updated docs in packages/docs/ if user-facing behavior changed
• For contract changes: storage layout, gas, and redeploy implications noted in the description