feat(relay): blocklist, priority list, and dedup TTL dashboard controls

[iceice400]

Summary

• Extend RelayConfig and PUT /api/config/relay with blocklist, priority_list, and dedup_ttl_seconds (default 300 s)
• RelayManager: blocklist check before dedup; priority nodes use allow_priority() (bypass burst gate, not per-minute cap)
• Hot reload via reload_filters() — no service restart for filter-only changes
• Configuration → Advanced: new Relay filters card with add/remove lists and dedup TTL

Why

Operators on rooftop gateways need to suppress noisy relay sources without SSH. Blocklist affects relay only — packets still appear in the live feed.

Type

• Bug fix
• Feature
• Docs
• Refactor
• UI
• Installer
• Region support
• Hardware change

Testing

• Local unit tests (7 pass; 2 API tests skip without PyJWT in dev env)
• Tested on hardware
• Dashboard tested on device

python -m unittest tests.test_relay_filters -v

Manual checklist (relay enabled, US915):

1. Configuration → Advanced → Relay filters — add blocklist node a3f2b1c0, save
2. Journal shows Relay rejected [blocklisted] for that source; packet still in live feed
3. Remove from blocklist → relay resumes (no restart)
4. Priority node under burst congestion relays with approved_priority
5. Dedup TTL 10 s vs 600 s — duplicate suppression window changes after save
6. Invalid ID notvalid → 400 from API

Hardware: RAK7248 or Pi + HAT · relay path (SX1262 USB or native)

Impact

• Parsing
• Relay
• TX (duty cycle unchanged at transmit layer)
• Radio driver
• Region logic
• UI + config API
• Installer only

Risks: Medium — touches relay evaluation order. Blocklist is earliest gate. Priority bypasses burst only. Dedup default preserved at 300 s.

AI-assisted?

• Yes