UI: Clarify indexer seed time and client torrent preservation settings for My Anonamouse

[jberlyn]

Problem

The previous indexer settings and localization strings led to confusion regarding how seeding limits and torrent preservation operate between Chaptarr and download clients (e.g., qBittorrent, rTorrent):

1. "Keep seeding permanently" (NeverMoveOnImport): The label suggested Chaptarr would force the download client to seed indefinitely. In reality, this setting controls Chaptarr's file import and cleanup lifecycle—ensuring files are copied/hardlinked rather than moved, and preventing Chaptarr from automatically removing completed torrents/data from the download client (exempting them from the "Remove Completed Downloads" task). It does not override or manage the download client's own seeding/ratio limits.
2. My Anonamouse "Seed Time" (SeedTimeHours): The help text stated that MAM requires 72 hours, but did not make clear that configuring a value passes a stopping limit directly to the download client (stopping seeding once 72 hours is reached), nor that leaving it blank allows the torrent to follow the download client's default seeding rules.

Change summary

• My Anonamouse Seed Time Help Text (MyAnonaMouseSettings.cs): Updated to explicitly state that the value is the time before the client stops seeding, and that leaving it blank uses the download client's default seeding rules.
• Indexer Preservation Label & Help Text (en.json): Renamed "Keep seeding permanently" (IndexerSettingsNeverMoveOnImport) to "Preserve torrents in client" and clarified that it always copies/hardlinks on import and prevents removal without overriding client-side limits.
• Cross-Reference Alignment (en.json, RTorrent.cs, DownloadImportModeResolver.cs): Synchronized existing references (ConvertMp3ToM4bHelpText, ConvertToQualityHelpText, RemoveCompletedDownloadsHelpText, and provider/resolver log messages) to use the new "Preserve torrents in client" naming.

Testing summary

• Verified string replacements and localization JSON syntax across all modified files.
• Confirmed that MyAnonaMouseSettingsValidator and SeedCriteriaSettingsValidator rules remain unchanged and allow null/empty SeedTimeHours without warnings.
• Verified that all internal identifiers and settings keys (NeverMoveOnImport, SeedTimeHours) are preserved so database configurations and API contracts remain unaffected.