feat: support keystone usb keyring

[Qkin-Keystone]

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] Adds Keystone hardware keyring type and integrates display names across account tree and accounts controllers.

• Keyring Controller:
  • Add KeyringTypes.keystone = "Keystone Hardware" in packages/keyring-controller/src/KeyringController.ts.
• Account Tree Controller:
  • Map KeyringTypes.keystone to wallet name "Keystone" and group prefix "Keystone Account" in packages/account-tree-controller/src/rules/keyring.ts.
• Accounts Controller:
  • Support KeyringTypes.keystone in keyringTypeToName → "Keystone" in packages/accounts-controller/src/utils.ts.

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