feat: add wallet reset confirmation phrase (#259)

[Killerjunior]

Summary

Adds a deliberate confirmation phrase requirement to the wallet reset confirmation modal to prevent accidental deletion of wallet secret keys, preferences, contacts, and transaction history.

Closes #259

Test Plan and Evidence

Happy Path

1. Open Settings -> tap Sign Out & Clear Wallet (or trigger secure storage inaccessible state).
2. The WalletResetConfirmModal appears displaying a clear breakdown of items to be deleted and a text input labeled Type "confirm reset" to confirm.
3. Type confirm reset (case/whitespace-insensitive).
4. The Delete Everything destructive button becomes enabled.
5. Pressing Delete Everything executes the wallet reset and clears the stored state.

Negative Path

1. Open the reset modal and enter an incomplete or incorrect phrase (e.g. confirm or reset).
2. The Delete Everything button remains disabled, preventing any execution of clearWallet().
3. Dismissing/canceling the modal resets the typed phrase input field so re-opening starts clean.

Automated Verification

• Executed unit tests in __tests__/WalletResetConfirmModal.test.tsx verifying phrase validation and accessibility behavior.

Self-Assessment

• Scope: The change matches the linked issue and contains no unrelated or unfinished work.
• Tests: Appropriate automated and manual evidence is included above, or a no-test justification is provided.
• CI: Relevant local checks pass and required CI checks pass on the latest commit.
• Documentation: Affected documentation, comments, examples, screenshots, and links are updated, or no update is needed.
• Known limitations: Limitations, assumptions, risks, skipped checks, and follow-up work are disclosed below.
• Acceptance criteria: Each issue criterion is mapped to implementation or verification evidence below.

CI Status

Local git branch feat/wallet-reset-confirmation-phrase committed and published to remote origin.

Documentation

Exported WalletResetConfirmModal in src/components/index.ts and src/features/wallet/index.ts.

Known Limitations

None known.

Acceptance Criteria

Acceptance criterion	Implementation or evidence	Status
Reset requires deliberate confirmation	User must type confirmation phrase in WalletResetConfirmModal	Pass
Confirmation phrase is clear	Phrase "confirm reset" explicitly shown in label and input placeholder	Pass
Reset is blocked until valid	confirmDisabled is true until exact phrase matches	Pass
Destructive action is labelled	Destructive action button clearly labeled "Delete Everything"	Pass
Flow remains accessible	accessibilityLabel and editable state properly configured	Pass

Screenshots or Recordings

UI Modal flow uses standard Expo React Native components with light/dark theme support.