Add cortexkit-provider-usage: shared wire types for the quota usage.get payload

[ualtinok]

Pure serde wire types (ProviderUsage, Usage, RateWindow, AccountInfo, SavedResets, CreditExpiry, ExtraWindow) extracted from ai-provider-quota's model.rs, following the cortexkit-model-catalog precedent (serde-only, no logic; serde_json dev-dep for wire-shape tests).

Why: the usage.get payload now has three+ consumers — the quota module (producer), ALF's router reads, astrocyte's capacity axis, and the ck quota renderer. A single shared definition means the shape can't drift without a PR every side reviews (this drift class bit the ck renderer twice: the ok-field filter and the rawUsedPercent addition).

Shape, not policy: read-time transform semantics (the quota module's banked-reset relaxation: used_percent zeroed + raw_used_percent carrying provider truth) are producer behavior documented on the fields but NOT enforced by these types.

Balance seam: intentionally NOT included — it was never populated and is wire-neutral; it joins this crate additively when the balance axis is designed.

Consumer-side swaps: ai-provider-quota rewires model.rs to a re-export (verified byte-identical wire, 358 tests + clippy + fmt green locally against a path dep); ck CLI swap SUBC will do post-publish; astrocyte ships v1 on a pinned mirror and swaps when convenient.

Publish is tag-driven per release.yml (cortexkit-provider-usage-v0.1.0) once merged.

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Summary by cubic

Introduces cortexkit-provider-usage, a shared serde-only crate for the quota usage.get JSON, so all consumers use the same wire shape and avoid drift. Adds the crate to the workspace; no behavior changes.

• New Features

  • New crate cortexkit-provider-usage with ProviderUsage, Usage, RateWindow, ExtraWindow, AccountInfo, SavedResets, CreditExpiry.
  • Serde-only with camelCase fields and optional field omission; documents banked-reset behavior (usedPercent vs rawUsedPercent), but does not enforce policy.
  • Wire-shape tests via serde_json; workspace updated to include the crate.

• Migration

  • ai-provider-quota: re-export these types; wire output remains identical.
  • Other consumers (ALF router, astrocyte, CK quota renderer): switch imports to cortexkit-provider-usage when convenient; no logic changes expected.

^{Written for commit 0ef4536. Summary will update on new commits.}