Accept bounded Experiment ZIP sources

[xor-machine]

What changed

• Add bounded Linux-only ZIP intake for Experiment check, authorize, and install.
• Accept one canonical experiment.cue member without extraction, normalize its source identity across directory and ZIP transports, and retain closed archive provenance.
• Reject unsafe paths, archive structure, metadata, types, flags, methods, ZIP64, mutation races, expansion, decoder uncertainty, and partial output before downstream effects.
• Extend the reusable source-adapter aggregate and private-copy mutation checks.

TDD evidence

• 8fc39f8 established the missing public ZIP surface; b17b1e6 supplied the minimal route.
• 918f079 made the hostile archive families RED; 439a6b9 implemented the bounded parser.
• c4a4309 proved the missing authorization/install ZIP surfaces; 798da9e routed them through the existing common store. The deeper common-store guarantees were inherited and are covered here by cross-transport and mutation checks.
• Of the hardening cases added in 9c2c529, ZIP-OUTPUT-001 was the new RED observation; 0a4a384 closed it. The other cases were retained as adversarial coverage.
• Later focused RED/GREEN pairs cover benign creator metadata and decoder setup (83631a5/fad3319), viable mutation oracles (214cdf3/8563e07), flags, usage, type, header, read-race, and late-decoder cases (7ac84b7/74b5820), NTFS compatibility (1d0a8e1/c6df909), Windows special types (727799b/828a9bf), and reserved watchdog status (720d5e7/3565b06).

Validation

• Source-adapter aggregate: 45/45, exact completion marker.
• Reusable aggregate harness: 23/23.
• Private ZIP mutations: 12/12 with production hashes restored.
• ./scripts/dev/ci-fast: 32 suites passed.
• ./tools/validate.sh --strict: passed.
• ./scripts/dev/docker-gate: 8 suites passed.
• ./scripts/dev/lint-scripts: passed.
• Diff and attribution checks: clean.

Supported claim: Linux ZIP intake only. This change does not execute or extract archive content and does not add runtime, image, or runner work.