Custom errors for Operator and Admin functions

[naddison36]

Summary

• Replace admin/operator-only revert strings with custom errors across ARM ownership, operator, pricing, fee, market, migration, and cap-manager paths.
• Keep user-facing revert strings unchanged for swaps, deposits, LP redeem request/claim flows, and public fee collection.
• Update tests and invariant handlers to expect the new custom-error selectors where applicable.

Contract Sizes

Current forge build --sizes ARM implementation sizes:

Contract	Runtime size	Runtime margin
OriginARM	22,484 B	2,092 B
EthenaARM	22,503 B	2,073 B
LidoARM	23,245 B	1,331 B
EtherFiARM	23,284 B	1,292 B

All four ARM implementations are under the 24,576 byte EIP-170 runtime limit.

forge build --sizes exited nonzero because some deploy/script contracts exceed the runtime limit, but the ARM contracts themselves are fine.

[clement-ux]

Really happy to see custom errors!