pnpm: Manifest identity spoof satisfies allowBuilds and runs attacker lifecycle

Summary

Keep build approval for opaque dependency sources byte-exact for GHSA-5wx6-mg75-v57r / CAND-PNPM-123.

Merged upstream commit bf1b731ee6 fixed the original name-only approval bypass by making build policy consume the resolved dependency identity. One collision remained: the generic peer-suffix normalizer also stripped parenthesized text from git, URL, tarball, file, and other opaque locators. Approval for one source string could therefore authorize a different attacker-controlled source whose locator normalized to the same value.

Security boundary

• Registry dependency identities still normalize legitimate peer suffixes and retain patch hashes.
• Git, URL, tarball, file, directory, and otherwise opaque identities must match the complete resolved locator byte for byte.
• Explicit denials use the same normalization as approvals.
• Ignored-build output preserves the exact opaque identity, so the key pnpm asks a user to approve is the key policy later checks.
• TypeScript pnpm and pacquet implement the same distinction between registry and opaque identities.

Exploit replay

• With allowBuilds approving foo@https://host/pkg.tgz, the upstream implementation also accepted foo@https://host/pkg.tgz(evil) because both passed through peer-suffix removal.
• An independent review found a second Rust-only form: foo@https://host/[email protected](good) and foo@https://host/[email protected](evil) collided because the parser selected the final @ and misclassified the opaque URL as a registry package.
• A final review found the same parser hazard in source-only locators ending in a semver-looking tail: approval for https://host/[email protected] could collapse https://host/[email protected](evil).
• The final patch rejects all three collision forms, applies the same exactness to deny rules, accepts exact opaque keys as positive controls, and continues to accept registry packages approved without their peer suffixes.

Files changed

• building/policy/src/index.ts and building/policy/test/index.ts normalize only parsed registry identities and retain exact opaque keys.
• pacquet/crates/package-manager/src/build_modules.rs passes snapshot identities to policy, matches TypeScript package-separator parsing, and preserves opaque locators.
• pacquet/crates/package-manager/src/build_modules/tests.rs covers exact approval and denial, all three collision forms, ignored-build output, and registry peer compatibility.