Add ARR submitted name folder naming option

[kw6423]

📌 Description

• Adds a new ARR submitted name folder naming option for WebDAV / external rclone paths.
• This keeps the release name sent by Sonarr, Radarr, or another client, such as the magnet dn value or uploaded torrent/NZB filename, instead of using a shorter debrid/provider title.
• This helps avoid imports where the ARR selected one release title but later sees a different folder name from Decypharr.

Example of the issue this fixes:

Sonarr selected/scored the full release title:

Real-Debrid later exposed a shorter/different torrent name:

With ARR submitted name, Decypharr creates the folder using the title ARR originally submitted:

That lets Sonarr import the same release successfully instead of rejecting it based on the shortened folder name:

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Target Branch Check (IMPORTANT)

• I confirm this PR is targeting the correct branch

Expected target:

• beta (for features)

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Changes Made

• Added folder_naming: "arr_submitted_name" and the ARR submitted name settings option.
• Uses the submitted magnet display name (dn) when available.
• Uses uploaded torrent filenames for .torrent uploads. Sonarr/Radarr submit torrent files using the cleaned release title as the multipart filename, so this matches the title used for detection/scoring. .magnet files preserve embedded display names and fall back to the uploaded .magnet filename when no display name is present.
• Sanitizes generated folder names and falls back to the infohash when the submitted name cannot produce a safe folder name.
• Updates qBittorrent-compatible name and content_path values so ARR clients see the folder Decypharr actually creates.
• Updated WebDAV folder naming docs, including the current global config key: folder_naming.
• Added tests for magnet display names, uploaded torrent filenames, unsafe names, and fallback behavior.

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Testing

• Tested locally

Steps:

1. Captured Sonarr -> Decypharr requests and confirmed the ARR-submitted name contained the full release title.
2. Checked Sonarr logs for the failed import case. Example:
   • Short folder parsed badly:
     Parsing string 'Season 01 1080p WEB-DL x265'
No matching series Season
   • Full ARR-selected title parsed correctly:
     Parsing string 'Example Show Season 01 S01 1080p WEB-DL x265'
Episode Parsed. Example Show - Season 01
   • Import later rejected files against the shortened folder:
     Episode 01x03 was unexpected considering the Season 01 1080p WEB-DL x265 folder name
Not all episodes have been imported for the release 'Season 01 1080p WEB-DL x265'
3. Verified the new option uses the original ARR-submitted release name, for example Example Show Season 01 S01 1080p WEB-DL x265.
4. Ran targeted tests:

go test ./internal/utils ./pkg/storage ./pkg/server/qbit

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Risks / Notes

• Existing folder naming options are unchanged.
• The docs previously referenced webdav_folder_naming, but the current global config key is folder_naming; this PR only updates the docs to match existing config behavior.
• Unsafe folder names are sanitized before use:
  • removes invalid/control characters and path separators
  • trims unsafe leading/trailing spaces or dots
  • rejects reserved names like CON, NUL, COM1, etc.
  • truncates very long names
  • falls back to the infohash if the result is empty or still unsafe

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Screenshots (if applicable)

• Settings dropdown now includes ARR submitted name as a folder naming option.
  

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Checklist

• Code builds successfully
• No console/log errors
• Reviewed my own code
• Target branch is correct