feat(keyring-controller): log mutex and atomic operation timings - #11267

Note

Low Risk
Observability-only refactor around existing mutex and atomic dispatch paths; locking semantics and secret handling are unchanged aside from new debug logs.

Overview
Adds opt-in lock timing diagnostics for @metamask/keyring-controller via DEBUG=metamask:keyring-controller*, without changing mutex behavior.

Mutex handling moves into a dedicated withLock helper that logs correlated Lock requested / Lock acquired / Lock released / Locked operation finished events for the controller and vault mutexes, with monotonic waitMs, holdMs, totalMs, and success. KeyringController now passes operation name labels (e.g. withKeyring, atomicUpdate, submitPassword) into every locked path so logs are attributable.

Atomic keyring work gets separate start/finish logs for the full operation run outside the controller lock, while atomicUpdate still shows up only as short controller-side commit windows. Logs deliberately exclude arguments, results, and error text.

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