[Feature Request] Add Backup/Fallback Pool Support in Pool Settings (like Bitaxe AxeOS)

[SoundMoneyWins]

• The current Apollo BTC / Apollo II web UI only allows configuring a single mining pool. I'm running the latest beta: Apollo OS 2.1 (v2.1.0-beta) and it still only supports one pool. If your primary pool goes offline (DDoS, maintenance, regional outage, etc.), the miner completely stops hashing until you manually log in and switch pools. This causes unnecessary downtime on a 24/7 device.

• Add support for a secondary Backup / Fallback Pool right in the Pool Settings page—similar to how Bitaxe's AxeOS handles it.

Something simple like this in the UI:

Primary Pool fields (already there):
Stratum URL
Username / Worker
Password
New Backup Pool section (add below or as tab/checkbox):
[ ] Enable backup pool
Stratum URL
Username / Worker
Password
Optional: timeout setting (e.g., switch after 60–120 seconds of failed connects)
Dashboard should show which pool is currently active ("Primary" or "Backup") with a status indicator.

• Why this is important:

Bitaxe has had reliable failover for ages—it just works.
Many of us run both Apollo and Bitaxe side-by-side; consistent UX would be huge.
Super high-impact for almost zero dev effort—prevents lost revenue from pool issues.
Aligns with the "set it and forget it" goal of the Apollo.

• Additional context / notes:

The underlying mining daemon (likely bfgminer or similar in Apollo OS) already supports multiple pools + automatic failover when configured in the backend. We just need the web UI to expose/save a second pool and pass it through to the config. No heavy lifting required. This would be one of the best QoL upgrades for home miners running Apollos.