Remove redundant client wrappers and unused code

[btsouth]

Inline 21 client-path forwarding functions, remove an unused Separator component, and drop three tests that only checked documentation or another test's source text. Platform-specific resolvers and behavioral tests remain.

Validation: client tests, packaging tests, TypeScript, and formatting checks.

Note

Remove redundant client path wrappers and unused code

• Replaces 22 dedicated client path helper functions in clients.rs with inline closures that call the shared config-path resolver, moving per-client path comments into the registry entries
• Deletes the unused Separator UI component from separator.tsx
• Removes stale or obsolete tests: a SECURITY.md regression test in security_doc.rs, Homebrew cask and Arch installer assertion blocks in homebrew-cask.test.ts and linux-packaging.test.ts
• Risk: removal of the SECURITY.md and packaging doc tests means those docs are no longer guarded by CI; stale content can reappear unnoticed

^{Macroscope summarized 1ef78b9.}