Design and implementation plan complete. Here's a summary:

Goal: Fail fast in intake stage when test infrastructure is broken, before wasting time/cost in the build loop.

• scripts/lib/pipeline-test-validation.sh — 6 validation checks in a new library module
• scripts/sw-lib-pipeline-test-validation-test.sh — ~18 tests (unit + integration + edge cases)

• scripts/sw-pipeline.sh — default variable + source new module
• scripts/lib/pipeline-cli.sh — --skip-test-validation flag + help text
• scripts/lib/pipeline-stages-intake.sh — call validate_test_infrastructure() after test detection
• package.json — register test suite

Checks: test command exists → test files exist → executable permissions → harness patterns (PASS/FAIL, set -euo pipefail) → shellcheck (optional) → mock directory patterns. Each check writes to a structured JSON report at .claude/pipeline-artifacts/test-validation.json.

• New lib module (not inline in intake) for clean separation and testability
• Shellcheck optional — skip with warning if not installed
• Harness pattern checks only for .sh files — non-bash projects skip those checks
• --skip-test-validation escape hatch for edge cases

Design doc: docs/plans/2026-03-09-test-infrastructure-preflight-design.md Implementation plan: docs/plans/2026-03-09-test-infrastructure-preflight-plan.md