feat: whitelist regex and SEL sync URLs by GitHub username

[Vidhin05]

Add GitHub username whitelist for regex and SEL sync

Summary

Adds two environment variables so community admins can whitelist trusted GitHub usernames instead of individual raw URLs for regex and SEL sync.

New environment variables

• WHITELISTED_REGEX_PATTERNS_URLS_GITHUB_USERNAMES — whitelists https://raw.githubusercontent.com/<username>/ URLs for regex sync
• WHITELISTED_SEL_URLS_GITHUB_USERNAMES — whitelists https://raw.githubusercontent.com/<username>/ URLs for SEL (Stream Expression Language) sync

Behavior

Provide a list of GitHub usernames. Any URL whose path starts with https://raw.githubusercontent.com/<username>/ is treated as whitelisted for the corresponding sync type. This lets you trust entire user/organization namespaces instead of maintaining long lists of raw URLs.

Example

WHITELISTED_REGEX_PATTERNS_URLS_GITHUB_USERNAMES=["Vidhin05"]
WHITELISTED_SEL_URLS_GITHUB_USERNAMES=["Vidhin05", "Tam-Taro"]

This whitelists all raw URLs under https://raw.githubusercontent.com/Vidhin05/ for regex and SEL sync; and https://raw.githubusercontent.com/Tam-Taro/ for SEL sync respectively.

Benefits

• Simpler config — whitelist usernames instead of many URLs
• Easier updates — new files or repos under a username are automatically allowed
• Same security model — only explicitly listed usernames are whitelisted