fix: reconcile close-position residual vaults by type

[liobrasil]

Problem

• FlowALP.closePosition() returns one vault per token type, and the return order is not guaranteed.
• FlowYieldVaultsStrategiesV2.FUSDEVStrategy.closePosition() previously assumed removeFirst() was always the collateral vault.
• That meant a close could either return the wrong vault type and revert, or silently destroy positive-balance residual vaults such as MOET overpayment dust.
• The strategy also stored per-vault swappers in contract config and did not remove them on burn.

What Changed

• Added _extractCollateralFromClosedPosition() to reconcile all vaults returned by closePosition() by type instead of trusting array order.
• Merged every returned vault of the requested collateral type into the final collateral vault.
• Added and stored a MOET -> collateral swapper so MOET residuals are converted back into the requested collateral before returning from close.
• Updated the mock strategy to use the same order-independent residual handling.
• Updated close-path comments in FlowYieldVaults so the interface describes the actual behavior.
• Extended burnCallback() to remove both stored swapper config entries when the strategy is destroyed.

Issues Solved

• Fixes close-path failures caused by assuming the first vault returned by FlowALP.closePosition() is always collateral.
• Prevents silent loss of MOET residuals / overpayment dust by converting them back into the requested collateral before returning from close.
• Makes close handling deterministic with respect to returned vault ordering by reconciling all returned vaults by type.
• Prevents contract config storage from leaking yieldToMoetSwapper_<id> and moetToCollateralSwapper_<id> entries after strategy burn.