feat(radarr): trigger search for existing monitored movies without files

[Kenshin9977]

Description

When a movie already exists in Radarr and is monitored but has no file, Seerr currently skips it entirely without triggering a search, even when preventSearch is set to false.

This PR adds a check in addMovie() so that when searchNow is true and the movie has no file yet, a search is triggered in Radarr via searchMovie(). This is consistent with the existing !monitored code path (line 140-184) which already updates and searches in the same way.

Use case: A user requests a movie via Seerr that was previously added to Radarr (monitored, no file). Previously, nothing happened. Now, Radarr will automatically search for it.

• Fixes Requested quality not applied in Radarr for existing movies #1822 (partially — search triggering only; quality profile updates are out of scope)

How Has This Been Tested?

Tested locally with Radarr running in Docker and Seerr in dev mode (pnpm dev):

1. Added a movie to Radarr as monitored with no file
2. Called addMovie() with searchNow: true via a test script
3. Verified Seerr logs show the new code path being triggered
4. Verified Radarr received and completed the MoviesSearch command for the movie

[info][Radarr]: Movie is already monitored in Radarr. {"movieId":1,"movieTitle":"Title"}
[info][Radarr]: Triggering search for existing monitored movie without file {"movieId":1,"movieTitle":"Title"}
[info][Radarr API]: Executing movie search command {"movieId":1}

Radarr command confirmation:

{"name": "MoviesSearch", "body": {"movieIds": [1]}, "status": "completed"}

• pnpm typecheck:server passes
• pnpm build passes

Checklist:

• I have read and followed the contribution guidelines.
• Disclosed any use of AI (see our policy)
• I have updated the documentation accordingly.
• All new and existing tests passed.
• Successful build pnpm build
• Translation keys pnpm i18n:extract
• Database migration (if required)

AI Disclosure

This PR was written with assistance from Claude Code. The fix logic and testing were reviewed and validated by a human.