[VULN-24] Error Messages Leak Internal Details

[lyncmi07]

Severity: Medium
Affected locations: routes/websites.ts:153-154, routes/git_websites.ts:74,122,163

Issue:
Raw backend errors are returned to clients, exposing internal topology, paths, and operational details useful for attacker reconnaissance.

Mitigation plan:

1. Replace client-facing errors with generic messages.
2. Log detailed diagnostics server-side with request correlation IDs.
3. Standardize error response schema.

Verification / tests:

• Tests assert no internal hostnames/stack details are returned in API error payloads.