Clarify allowance cards and source readings

[sarthakagrawal927]

As credit and reset information grew, the provider cards put balances, grants, expiry and raw source metadata into a crowded text stack. Keep the existing two cards and styling, group credits and reset grants under clear labels, and put complete source/check details in native disclosures. Scheduled resets stay beside their allowance meters; failed checks clearly distinguish stale readings from unavailable data.

Claude grant counts remain conditional on CLI notices. Missing counts stay unknown and link to Claude Settings > Usage. Full/5-hour desktop grant type and expiry retrieval remain unsupported; no new authentication adapter or reset-consuming action is included.

Validation:

• 12 focused SwiftPM tests passed on a clean main-based checkout, including nil/zero/singular/plural grant labels and provider parsing.
• Native full-window renders reviewed at 960, 1180 and 1440 points, plus missing, depleted, stale and unavailable states.
• Running native preview verified both live allowance readings, disclosure behavior and the official Claude Usage link destination.
• v2 design completion check and git diff --check passed.

Refs #15. The grouping is ready to release; the provider source limitation remains tracked separately in that issue.