Add .env and deployrr_constants validation to health check feature

[SimpleHomelab]

Description

After uninstalling an app (e.g., xpipe-webtop), lingering variable definitions in /opt/deployrr/deployrr_constants (or .env) can cause errors on every Deployrr routine execution.

Error Observed

/dev/fd/63: line 20: XPIPE-WEBTOP_GPU=intel_amd: command not found

This error appeared every time a user ran a Deployrr command, even though xpipe-webtop had already been removed. The root cause was a stale variable definition for xpipe-webtop remaining in deployrr_constants.

Environment

• Deployrr 6.0 rc2
• Ubuntu 24 via Proxmox VM
• GPU passthrough configured (working with Jellyfin)

Steps to Reproduce

1. Install an app that sets variables in deployrr_constants (e.g., xpipe-webtop with GPU config).
2. Uninstall the app via Deployrr.
3. Run any Deployrr routine — the error appears because the variable definition was not cleaned up.

Current Workaround

Manually edit /opt/deployrr/deployrr_constants and remove the lingering variable definition.

Proposed Solution

Expand the health check feature to include validation of .env and /opt/deployrr/deployrr_constants files:

• Stale variable detection: Flag variables referencing apps that are no longer installed.
• Syntax validation: Check for improper variable definitions that could cause command not found errors (e.g., hyphens in variable names like XPIPE-WEBTOP_GPU which bash interprets as a command).
• Cleanup recommendation or auto-fix: Offer to remove or comment out stale entries during health check.

Reference

• Discord thread — reported by dial1830