test: parallelize BATS across semantic suites

[junior-ricon]

Summary

• split the former 86-test obfuscation suite into semantic obfuscate, deobfuscate, and hook/commit-cycle owners
• disable Bats 1.13 within-file parallelism and let Rush schedule whole files across eight workers
• update the runner contract to require cross-file-only scheduling

Why

Bats 1.13 within-file scheduling uses one-second semaphore polling, documented in KnickKnackLabs/template#7. Notes was explicitly enabling that path. Splitting by behavior gives Rush useful file-level scheduling units while keeping each test body unchanged.

All 86 test titles and bodies were mechanically verified as preserved byte-for-byte.

Validation

• focused suites: 38/38 obfuscate, 28/28 deobfuscate, 20/20 hook/commit-cycle
• runner contract: 9/9
• full suite: 412 BATS and 9 Python tests
• all eight Codebase lints
• mise run doctor
• readme build --check
• Bash syntax and git diff --check
• Fold pre-commit and pre-push (zero failures; expected no-upstream and GitHub merge-signature warnings before first push)

One comparable local observation on exact settled main ef2d0b19 took 171.57s. The exact candidate took 135.23s, 36.34s (21.2%) faster. This is one source-supported before/after observation, not a universal benchmark.