Shared Rust Build Cache via sccache

Shared Rust Build Cache via sccache

Status: Delivered
CAS: CAS-3615
Delivered: 2026-05-18
PR: #970

What changed

Adopted shared sccache configuration for Rust compilation so repeated builds across worktrees and agents reuse compiled artifacts.

Why it matters

• Reduces incremental build latency for Rust paths.
• Lowers duplicate compilation churn during rapid CI/debug loops.
• Complements CAS-3611 dependency-sharing work to reduce workstation resource pressure.

Technical anchors

• .cargo/config.toml
• scripts/rust-lint-gate.sh