Bring your own server: install command, terms, management fee

Imported from GitHub issue El-SaMa/oma#154 by @El-SaMa.

• Customer portal: add server -> one-line install command with token
• Management fee product (per server or per app, operator decision)
• Terms: no uptime promise on customer infrastructure
• Health reporting so support can show the cause of outages

Design doc: https://claude.ai/code/artifact/8e38762a-5369-45d1-a64d-fce59d2e560b