Enumerates every raw NDI source string visible to the local NDI finder for ~5 seconds and prints unique ones, then exits. Bypasses NdiSourceParser so it surfaces sources that the parser would otherwise reject — useful for confirming the on-the-wire format Teams (or any other producer) is actually emitting on a given setup.
Used directly to diagnose the Teams 'MS Teams' vs. 'Teams' brand-prefix mismatch fixed in the previous commit; left in as a permanent debug tool for future setup issues.
