Post-release papercuts: fail-closed lockfile check, llvm classifier, version-agnostic docs

[ciaranra]

Three post-release papercuts (plan cross-reviewed with Codex; its fail-closed adjustment adopted):

1. Dependency-integrity check: fail-closed handling of untracked lockfiles. The lockfile-currency loop swept in the gitignored generated doc-test lock (rg --files lists it despite the ignore, via negation-pattern divergence), and a stale local copy broke just check-all with a misleading --locked error. New predicate: tracked → validate; gitignored (documented generated artifacts, rationale lives in .gitignore) → skip with message; anything else → fail ("commit it or gitignore it with a rationale"), so a lock that should be committed cannot slip through. All three paths tested (including a planted unexpected lock).
2. pecos-rslib-llvm classifier said POSIX :: Linux but we publish macOS and Windows wheels — now OS Independent (matching pecos-rslib; pecos-rslib-cuda deliberately stays Linux-only, cuQuantum is Linux-only).
3. docs/user-guide/cli.md hardcoded the release version in example output, forcing doc edits on every bump — now a v<version> placeholder.