feat: scan DSH plugins during checkup

[Mr-Lucky]

Summary

• Discover installed DSH plugin directories and include them in local health checkup code-safety scans.
• Fold DSH findings into health scores, reports, CLI output, and audit records.
• Tolerate transient files that disappear while enforcing GitHub source acquisition limits.
• Add coverage for DSH discovery/scanning, report and score generation, CLI integration, and checkout race conditions.

Type

• Bug fix
• New feature / detection rule
• Refactoring
• Documentation

Testing

• npm run build passes
• npm test passes (610 tests)
• Manually tested the change

Related Issues

Closes #

[github-actions]

AgentGuard PR Review

I found a couple of concrete regressions in the DSH checkup changes.

1. severity: high — src/cli.ts / src/feed/dsh-discovery.ts / src/tests/cli-checkup.test.ts

   • What can go wrong: the CLI now counts and scans any direct dependency whose package directory exists, and only excludes @goplus/agentguard based on the installed package’s self-reported package.json name. A malicious or tampered package can rename itself to @goplus/agentguard to evade both discovery and scan, so a risky plugin can be silently skipped.
   • Concrete fix: exclude the managed package by the dependency coordinate from the profile manifest (dependencyName === '@goplus/agentguard') before any filesystem lookup, and do not use the installed package’s name field for trust decisions.

2. severity: medium — src/checkup/dsh.ts

   • What can go wrong: DSH plugin scan results are now converted to code-safety findings using per-finding severity, but the score deduction is still capped at 100 only after summing all deductions. If a single plugin produces many findings, the code-safety score can underflow before clamping and distort downstream scoring/tiers compared with the previous model.
   • Concrete fix: clamp per-plugin or per-finding deductions incrementally, or compute deductions from a bounded normalized model so the score cannot be driven far below zero before the final clamp.