COR-1646: distinct malicious verdict at install time (npm/pip)

[juangaitanv]

COR-1646: Distinct malicious verdict at install time (npm/pip)

Known-malicious packages already blocked at install time, but were folded into the generic vulnerable verdict. This surfaces them as a distinct, blocking malicious signal on the corgea npm / corgea pip wrappers (yarn/pnpm/uv inherit via the shared precheck path).

What changed

• New VerdictStatus::Malicious (src/precheck/mod.rs), separate from Vulnerable, carrying all matches.
• Classifier VulnMatch::is_malicious() = malware flag OR advisory_id starts with MAL- (src/vuln_api/mod.rs). The MAL- prefix keeps the label correct even if this CLI ships before the worker that sets the authoritative flag.
• BlockReason::Malware with top precedence and a distinct refusal (src/precheck/verdict.rs, render.rs):
  Refusing to run install: known MALICIOUS package(s) detected. Pass --force only if you are certain.
• Render: known malicious: headline in both named and tree arms; separate malicious counts in the text summary (omitted when zero).
• --json: new "status": "malicious", per-match "malware" boolean, and a malicious count in each summary object. schema_version stays 1 (purely additive).
• --force overrides the malicious block unchanged and propagates the package manager's exit code.
• Refreshed --force help (src/main.rs) and skills/corgea/SKILL.md copy; swept generic-vulnerable test fixtures off MAL- ids to CVE- so they stay Vulnerable under the new prefix rule.

Testing

• cargo build --release ✓
• cargo test ✓ — all suites green (0 failed); +9 new tests: distinct malicious block + exit, --force override, mixed CVE+MAL tally, malicious-in-tree path, and a guard that a merely-vulnerable run's output never contains the string "malicious".
• cargo clippy --all-targets -- -D warnings ✓, cargo fmt --check ✓

Pre-existing cargo audit advisories (transitive quick-xml, git2) are unrelated — this diff touches no Cargo.toml/Cargo.lock.

Acceptance (COR-1646)

• Distinct Malicious verdict, separate from Vulnerable, with its own message
• corgea npm / corgea pip block a known-malicious version with a distinct message + non-zero exit
• --force overrides
• A merely-vulnerable package is never labeled malicious

Depends on the vuln-api change (Corgea/vuln-api, COR-1646) that emits the authoritative malware flag from /check; the MAL- prefix fallback means this CLI is correct regardless of deploy order.

Linear: COR-1646 · Parent: COR-1632 (POL-01)

[cursor]

Finding: src/verify_deps/registry.rs:535 — CI rust-tests is currently red. Evidence: the GitHub job failed with -D clippy::question-mark on lines 535-540 (this block may be rewritten with the ? operator) and exited 101, while the PR body says clippy passed. Impact: this branch cannot be merged/released with required checks failing, independent of the install-verdict behavior. Fix: apply the clippy suggestion at that block (use let r = suffix.strip_prefix('c')?; for the final fallback) or otherwise make ./harness ci pass on the PR branch.

  

_{Sent by Cursor Automation: pr-flow}