feat: keyring controller error

[montelaidev]

Explanation

References

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
• [ ] I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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[!NOTE] Introduces KeyringControllerError with codes/data/causes and refactors the controller and tests to use it, improving error wrapping and stability.

• Core (keyring-controller):
  • New error class: Add src/errors.ts defining KeyringControllerError (supports code, data, cause and legacy originalError, JSON/string serialization).
  • Error refactor: Replace generic Error throws with KeyringControllerError across src/KeyringController.ts (e.g., exportSeedPhrase, exportAccount, signing, user ops, vault ops, validation helpers).
  • Improved wrapping: signTypedMessage now wraps underlying errors with KeyringControllerError, preserving original cause.
  • Misc: Minor guard/typing tweaks (explicit HD type checks) and internal deadlock-safe state-change listener logic in tests.
• Tests:
  • Update expectations to use KeyringControllerError class and KeyringControllerError messages from ./constants.
  • Add comprehensive tests for error codes/data/causes and propagation from hardware keyrings.
• Config:
  • Increase Jest coverage threshold for branches to 95.5 in jest.config.js.

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