refactor: migrate PreferencesController to @metamask/messenger

[cryptodev-2s]

Explanation

This PR migrates PreferencesController to the new @metamask/messenger message bus, as opposed to the one exported from @metamask/base-controller.

References

• Related to Implement messenger delegation #5626

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed, highlighting breaking changes as necessary
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes

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Note

Migrates PreferencesController to the new @metamask/messenger API and renames metadata anonymous to includeInDebugSnapshot, with corresponding test, config, and docs updates.

• Preferences Controller:
  • Migrate from RestrictedMessenger (@metamask/base-controller) to Messenger (@metamask/messenger); import BaseController/deriveStateFromMetadata from @metamask/base-controller/next.
  • Rename metadata property anonymous to includeInDebugSnapshot across state metadata.
  • Update PreferencesControllerMessenger type to use @metamask/messenger and adjust allowed events typing.
• Tests:
  • Replace helper messenger construction with root Messenger + delegated namespace; update imports/types accordingly.
  • Update metadata derivation calls to use includeInDebugSnapshot.
• Build/Config:
  • Add dependency @metamask/messenger and TS project references.
• Docs:
  • Update README dependency graph to show preferences_controller --> messenger and add eip_7702_internal_rpc_middleware --> controller_utils.
• Changelog:
  • Document breaking changes for messenger migration and metadata rename.

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[mcmire]

LGTM!