Port upstream 0.55.0: optimize OpenCodex pricing

[Finesssee]

Summary

• port upstream CodexBar v0.55.0 OpenCodex pricing hot-path optimization from Price OpenCodex usage once per entry and stop per-entry catalog/overlay reloads steipete/CodexBar#3136
• load the cached models.dev catalog once per OpenCodex aggregate and pass an immutable pricing snapshot through row pricing
• preserve historical request-day pricing and existing custom-pricing precedence
• avoid per-entry models.dev cache metadata checks while keeping output semantics unchanged

Upstream evidence

• target release: v0.55.0
• upstream commit: d8d03a122 / Price OpenCodex usage once per entry and stop per-entry catalog/overlay reloads steipete/CodexBar#3136

Validation

• cargo test -p codexbar opencodex --no-fail-fast -> 6 passed
• focused rustfmt on touched Rust files
• git diff --check -> pass

Scope

Isolated OpenCodex spend performance port. No provider-auth, UI, or version bump changes.

[Finesssee]

Thermo-nuclear re-review

Previous finding is closed: the bulk pricing snapshot retains the cache artifact by shared Arc ownership instead of cloning the models.dev catalog. Focused OpenCodex tests and strict Clippy pass.

Verdict: APPROVED.