[WIP] Fix code for comments in review thread #1917

[Copilot]

• Fix 1 (line 151): Guard find "$CACHE_DIR" with if [ -d "$CACHE_DIR" ] check and add || true fallback
• Fix 2 (line 183): Escape quarantined file output with sed 's/^/| /' to prevent GH Actions command injection
• Fix 3 (line 185): Preserve directory structure in quarantine destination to avoid filename collisions
• Fix 4 (line 582): Make TTL key/restore-keys transformations independent instead of gated by single file-wide check
• Run tests to validate changes