Document Plex watchlist rule behavior and cloud dependency

[enoch85]

Summary

The docs should clarify how Plex watchlist rules behave in Maintainerr and what users should expect when Plex cloud endpoints are unavailable or slow.

Why this needs documenting

Recent user reports showed understandable confusion around the Plex watchlist rules:

• users assumed Watchlisted by only checks their own watchlist
• users assumed removing a Plex friend would stop Maintainerr from scanning that person
• users expected reauthing Plex or changing the local Plex IP to fix watchlist lookup timeouts
• users did not realize these rules depend on Plex cloud endpoints, not just the local Plex server

The code path confirms:

• Watchlisted by and Is Watchlisted scan all users returned by the Plex server account list, then try to resolve Plex.tv/community usernames and UUIDs for watchlist lookups
• there is no setting today to exclude a specific user from the scan
• private watchlists can legitimately trigger warnings
• full library rule execution repeats Plex cloud watchlist lookups across many items, so Test Media can succeed while a full run times out with ECONNABORTED
• changing the local Plex IP is usually irrelevant for this path because the watchlist lookups hit Plex cloud endpoints

Requested doc changes

1. Add a docs section for Plex watchlist rules explaining that Watchlisted by and Is Watchlisted do not only check the current user.
2. Explicitly state that these rules scan all users returned by the Plex server account list.
3. Document that there is currently no per-user exclude option for Plex watchlist scanning.
4. Explain that private watchlists can produce expected warnings.
5. Explain that these rules depend on Plex cloud services (plex.tv / community.plex.tv), not only the local Plex server.
6. Add a troubleshooting note that Test Media may work while full rule runs fail if Plex cloud calls time out under repeated lookups.
7. Call out that Watchlisted by is experimental and may be more fragile than purely local metadata rules.

Suggested troubleshooting guidance

• Verify the affected user is still actually returned by the Plex server account list.
• Verify the watchlist is public if it is expected to be visible.
• Do not rely on local Plex IP changes to fix this specific issue path.
• If Test Media works but full runs fail, note that this may be an implementation limitation rather than a local configuration error.

Follow-up product work

This is partly a docs gap, but it also points to a product improvement:

• cache or memoize watchlist/user lookups once per rule run instead of repeating them per media item