Add Steam Workshop updates for DayZ mods

[partyplatter08-lab]

Closes #215

Summary:

• Detect Steam Workshop mod directories by reading meta.cpp files under the configured mods-updater.path.
• Store each detected publishedid in mods.yml as steam-workshop-id.
• Check Steam Workshop metadata through Steam's published-file details API and compare against the cached Steam time_updated value.
• Treat first-time detected Workshop mods as uncached, so DayZ meta.cpp timestamps are not compared against Steam API Unix timestamps.
• Download Workshop updates through SteamCMD with workshop_download_item.
• Add mods-updater.steam-workshop-app-id, defaulting to DayZ's Workshop app id 221100, so DayZ server installs do not have to reuse the dedicated-server app id for Workshop downloads.
• Preserve updater profile behavior: NOTIFY reports updates, MANUAL downloads Workshop content into autoplug/downloads/steam-workshop, and AUTOMATIC installs the downloaded Workshop content back into the existing mod folder.

Validation:

• mvn -q -Dtest=SteamWorkshopModTest,SteamCMDTest#buildsWorkshopItemCommand test
• mvn -q -DskipTests package
• git diff --check f9b04ef..HEAD

Note: AI was mostly used for this PR. I, the human, validated it.

[Osiris-Team]

@partyplatter08-lab I updated the bouty terms, please read them and ensure your PR follows the terms:

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[Osiris-Team]

@partyplatter08-lab please give me a short confirmation that you read the terms so that I can start reviewing, thanks!

[Osiris-Team]

Closed due to violation of terms