feat: implement token update

[ddiestra]

Description

• As part of the update on the Guides, we need to have the token update for when CVC needs to be updated in a card token.

Testing required outside of automated testing?

• Not Applicable

Screenshots (if appropriate):

• Not Applicable

Rollback / Rollforward Procedure

• Roll Forward
• Roll Back

Reviewer Checklist

• Description of Change
• Description of outside testing if applicable.
• Description of Roll Forward / Backward Procedure
• Documentation updated for Change

[ducktape-agents]

LGTM. Clean implementation of token update via PATCH, consistent with existing create token patterns.

[ducktape-agents]

LGTM. Clean implementation of token update via PATCH with proper content type, error handling, and telemetry consistent with existing patterns.

[ducktape-agents]

This debug print logs all HTTP headers including API keys to stdout — remove before merging.

[ducktape-agents]

Debug print statement left in production code — remove before merging.

[ducktape-agents]

This prints the full unmasked API key via request.allHTTPHeaderFields. The debugHeaders masking above is unused. Remove all debug prints before merging, or at minimum use debugHeaders instead.

[ducktape-agents]

Debug print left in production code — remove before merging.

[ducktape-agents]

-only-testing UnitTests/CardExpirationDateUITextFieldTests limits CI to a single test class, so UpdateTokenTests and all other tests won't run in CI.

[ducktape-agents]

AnyCodable(self.mask) when self.mask is nil creates a non-nil AnyCodable wrapping nil, which serializes as "mask": null in the merge-patch JSON — this will clear the mask on the server. Use self.mask.map { AnyCodable($0) } instead so the field is omitted when not set.