test: cover ComplianceRegistry.all() and stop excluding index.ts from coverage (fixes #45)

[hanu-14]

Adds tests asserting ComplianceRegistry.all() returns in-sync S3 reports with valid controls, and removes the index.ts exclusion from jest coverage collection (now 100% line coverage).

[alphacrack]

This is the strongest PR of the set — the toContainEqual(S3BucketCompliance.report()) sync assertion is exactly the drift-catcher #45 asked for, the per-entry shape checks will hold future resources to the same bar, and removing the !src/**/index.ts coverage exclusion closes the blind spot (note it also un-hides the resources/*/index.ts barrels, so thanks for confirming the suite still passes with coverage collected there).

Merges last since it's stacked on #56/#57.

[alphacrack]

Re-checked against the new main: MERGEABLE/CLEAN — including jest.config.js, which today's merges didn't touch. Approval stands.

One sequencing note: this branch is stacked above #57, so its diff currently carries #57's fields.test.ts as-is. Preferred path is #57's fix lands first and the stack merges in order. If #57 stalls, merging this PR would bring in #57's tests without the fallback cases — acceptable, but then #57 gets closed as superseded and the fallback cases become a small follow-up.

[hanu-14]

Thanks for the review and approval, alphacrack! I’ll rebase this branch on top of #57 to ensure the diff reflects the latest changes, and I’ll update the PR description to clarify the sequencing. If #57 stalls, I’ll merge this PR and address the fallback cases in a follow-up.