Reduce Cargo build artifact size

[terasakisatoshi]

Summary

• disable debuginfo in the workspace dev and test profiles while retaining Cargo's default debug assertions and overflow checks
• add a stripped, non-incremental ci profile and use it for hosted tests and facade doctests
• report Cargo artifact and filesystem usage in CI, and document the measurements and rejected integration-test consolidation experiment

Motivation and impact

The workspace produces many test executables containing generic numerical kernels, so duplicated debuginfo accounts for a large share of target usage.

On a fresh Apple Silicon target directory, debug = 0 reduced test artifacts from 1,717,360 KiB to 824,372 KiB (52.0%) and development artifacts from 1,082,416 KiB to 497,244 KiB (54.1%). The CI profile reduced test artifacts further to 703,520 KiB, approximately 59.0% below Cargo's default test profile.

Coverage retains its instrumentation-owned profile. An integration-test consolidation experiment was rejected because its additional 3.5% reduction did not justify weakened process isolation and less convenient focused test commands.

Validation

• cargo fmt --all -- --check
• cargo test --workspace
• fresh-target build measurements recorded in docs/2026-08-09-cargo-artifact-reduction.md

[github-actions]

Repository rules review

Repository rules review (2570a4e391d4df75359ae043b620e7d79a3e64b0...fd96e76de4e47c76d0d769c010a9188d75f2b3c4)
Verdict: pass
LLM review: 1 chunk(s) (5496 chars) in 8.8s; 0 finding(s) returned, 0 kept, 0 dropped by diff-anchor filtering.
No findings.