fix: restore host password copy actions

[ZacharyZcR]

Summary

• add host-list actions to copy stored SSH and sudo passwords
• reuse the existing password endpoint with clipboard fallback for Firefox/browser contexts
• keep the share-host action visible beside the new credential actions for RBAC sharing

Refs Termix-SSH/Support#749

Validation

• npm run type-check
• npx eslint src/ui/sidebar/SidebarTree.tsx src/types/ui-types.ts
• git diff --check