Audit: Fix post-script reference to non-existent file

[k-rister]

Jira: PERFNFV-432
Severity: Critical | Audit: 2026-08-01

rickshaw.json:9 references %utility-dir%packrat-post-process but this file does not exist.

• Create packrat-post-process script, or remove controller block
• Fix unquoted variables in packrat script
• Add .gitignore
• Add fork-check workflow