Port v0.57.0: normalize reserve telemetry pricing alias - #490

What this ports

Ports upstream commit 57ddfdbf70f2de23c1b5bd8fdb3c660944a22b4a from steipete/CodexBar for the reserve telemetry pricing alias.

The local Rust equivalent normalizes the exact gpt-reserve alias to gpt-5.6-luna, including trimmed, provider-qualified, and case-insensitive input forms. The shared normalizer is used by both fresh usage and cached pricing paths.

Scope

Changed files:

• rust/src/core/cost_pricing.rs
• rust/src/core/cost_pricing_tests.rs

The port intentionally excludes upstream Swift generated pricing, parser/cache, UI, documentation, and changelog surfaces that do not map to this local Rust implementation.

This PR is stacked after the numeric parsing lane in PR #489:

• Base: port/micro-0.57.0-opencodex-numeric
• Head: port/micro-0.57.0-reserve-pricing

Validation

• cargo fmt --all -- --check — passed
• git diff --check — passed
• Focused Rust test attempted: core::cost_pricing::tests::gpt_reserve_alias_uses_luna_pricing
• Focused test was blocked before test execution by the local linker environment: Rust resolved link.exe to Git usr/bin/link.exe, which rejected MSVC linker arguments with link: extra operand.

Oracle reviewed the implementation and approved staging, commit, push, and this stacked PR. The PR remains open for review; no merge is requested by this porting step.