fix(skills): vendor the support files the vendored skills point at

The vendored SKILL.md files were byte-identical to upstream, but the
playbooks, templates and schemas they reference were left behind in the
original repos, so a loading skill pointed at a file that does not exist
anywhere in this repository.

Vendored 1:1 into each skill directory (so they survive
`cp -r skills/* ~/.hermes/skills/`):

- plays/ for api-security-review, code-review-security, sca-audit,
  secrets-scan, web-security-review (OWASP/secure-agent-playbook)
- templates/finding.md for the four OWASP skills that cite it
- schemas/finding.schema.json for cve-triage, patch-prioritization,
  dependency-scanning (UnitOneAI/SecuritySkills)
- docs/sarif-output.md, docs/fixer-policy.md and
  docs/normalized-json-output.md for dependency-scanning

Path fixes, the only edit to vendored text:
- the three UnitOneAI skills referenced ../../../schemas/ and ../../../docs/
  which assumed upstream's skills/<category>/<skill>/ depth; this repo is
  flat, so the links now resolve inside the skill directory
- safedeps told the agent to run <skill_dir>/../../check_deps.py while the
  script is vendored next to SKILL.md; corrected to <skill_dir>/check_deps.py
  and documented the script's exit codes (1 = finding, not a crash)
- NOTICE.md records the new files, the path edits, and the remaining known
  gaps (hermaguard's kensei-pipeline references, the ASVS dataset citations,
  and hermaguard being behind upstream)

Verified: every backticked path in every SKILL.md now resolves;
check_deps.py runs from the installed location and returns live OSV.dev
data ([email protected] -> 2 advisories); hermaguard's 46 tests still pass.

skills/safedeps/SKILL.md

@@ -23,12 +23,12 @@ one, run the checker and use its real output instead of your own
 recollection of which versions are safe.
 
 ```bash
-python3 <skill_dir>/../../check_deps.py <package>@<version>:<ecosystem>
-python3 <skill_dir>/../../check_deps.py path/to/requirements.txt
+python3 <skill_dir>/check_deps.py <package>@<version>:<ecosystem>
+python3 <skill_dir>/check_deps.py path/to/requirements.txt
 ```
 
-(`<skill_dir>` is this file's directory; the script lives at the repo/plugin
-root as `check_deps.py`. Ecosystems: `npm`, `PyPI`, `Go`, `crates.io`,
+(`<skill_dir>` is this file's directory; the script is vendored next to this
+file, as `check_deps.py`. Ecosystems: `npm`, `PyPI`, `Go`, `crates.io`,
 `Maven`, etc. -- omit `:ecosystem` and it defaults to `npm`.)
 
 The script prints one of two things per package, straight from OSV.dev:
@@ -42,6 +42,11 @@ VULN  npm:[email protected] -- 2 advisory(ies):
 
 ## What to do with the output
 
+Exit code is `0` when every package is clean, `1` when at least one advisory
+was found, and `2` when OSV.dev was unreachable -- `1` is a finding, not a
+crash. (The manifest mode only accepts files named `requirements.txt`,
+`package.json`, `package-lock.json` or `go.mod`.)
+
 1. If a package you're about to add/bump shows `VULN`, do not use that
    version. Use the version named in `fix:` instead (or newer).
 2. If no fixed version is listed, tell the user there's an open advisory