Add Spokes App

[PCBeeQC]

What does this PR do?

Adds Spokes to the CasaOS App Store.
Spokes is a self-hosted, secure communication platform for friend groups, families, and small businesses. It features real-time chat, voice, and video channels with zero-trust security.

Configuration Notes for Reviewers:

• Architecture: Set to amd64.
• Ports: Spokes uses LiveKit for voice/video. Due to WebRTC NAT traversal requirements, the TCP fallback (7881) and UDP range (50000-50499/udp) must be mapped 1:1:1 to the host. This is explicitly noted in the UI tooltips for users.
• CI Validation Note: The validation script successfully checks and passes Spokes. However, the CI Action currently fails later in the pipeline when validating Etherpad (which contains duplicate YAML keys for ports and volumes in its x-casaos block).

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud