feat: experimental MetaSwap intent delegation manager

[hanzel98]

Summary

Experimental purpose-specific MetaSwapIntentDelegationManager for two MetaSwap flows (not a drop-in for the generic DelegationManager).

Intent	Product	User signs	Redeemer may change
ExactCalldata	Gasless exact swap	Full batch hash	Nothing
FlexibleSettlement	Limit order	Economics + approval shape	Route / aggregatorId only

Also includes experimental flexible-only prototypes (Hookless, ExecutionBuilder) for comparison.

Gas (approve + swap, EIP-7702, DirectECDSA)

Approach	Gas
Generic ExactBatch + LimitedCalls(1)	~231k
Unified ExactCalldata	~159k (~31% cheaper)
Unified FlexibleSettlement / Hookless	~167k
Unified + ERC1271	+~1.9k vs DirectECDSA

Included

• Contracts: intent manager + shared bases + two flexible prototypes
• Docs: documents/MetaSwapSpecializedDelegationManagers.md
• Tests: intent + specialized suites (100% line coverage on new manager contracts)
• Deploy: script/DeployMetaSwapIntentDelegationManager.s.sol
• Verify: script/verification/verify-metaswap-intent-delegation-manager.sh

Limits

• One root delegation, one self-caveat, batch/default only
• No chains / try-mode / pause / enableDelegation
• Gasless expiry remains off-chain

Test plan

• forge test --match-contract 'MetaSwapIntent|MetaSwapSpecialized'
• forge coverage --match-contract 'MetaSwapIntent|MetaSwapSpecialized' --report summary (manager src files at 100% lines)
• Dry-run deploy script with SIGNATURE_MODE=0
• Confirm verify script reads META_SWAP_INTENT_DELEGATION_MANAGER_ADDRESS + SIGNATURE_MODE

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Note

High Risk
New on-chain swap/limit-order authorization moves funds via approvals and MetaSwap routes with documented trust in delegates and balance-based min-output checks; specialized managers bypass generic caveat composition.

Overview
Adds experimental MetaSwap settlement paths alongside the generic delegation manager: a unified MetaSwapIntentDelegationManager (ExactCalldata gasless swaps vs FlexibleSettlement limit orders with redeemer-chosen routes), shared MetaSwapDelegationManagerBase, and flexible-only prototypes (Hookless, ExecutionBuilder). Also introduces alternate specialized managers (GaslessSwapDelegationManager, MetaSwapMinimalDelegationManager) that reuse existing enforcers or inline enforcement for EIP-7702 swap/limit-order profiles.

New caveat enforcers cover MetaSwap batch shapes and settlement economics— notably MetaSwapFlexibleSettlementEnforcer (one-shot consumption, min output, retry on revert)— plus MetaSwap7702CalldataEnforcer, batch/calldata validators, and adapter/prefund variants. DeployCaveatEnforcers deploys the flexible settlement enforcer; new deploy/verify scripts and META_SWAP_INTENT_DELEGATION_MANAGER_ADDRESS env support the intent manager. Docs describe terms encoding, trust assumptions, gas comparisons, and limitations.

Broad Foundry test suites exercise redemption, replay/cancel, signature modes, insufficient output retry behavior, and gas benchmarks vs generic enforcer stacks.

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