Add AdGuard Home as an installable Tachyon component (component card with
check/update/remove/rollback/enable/disable) backed by providers/adguard
(validator + runtime) and an init.d service.
Backend:
- action.uc: install/remove/enable/backup/rollback/dispatch/releases for
'adguard' (tar.gz from AdguardTeam/AdGuardHome, OpenWrt->AdGuard arch map)
- updater.uc: adguard asset selection; updates.uc: valid_component_name and
automatic update checks
- runtime.uc: generates AdGuardHome.yaml from UCI (upstream=single-box DNS,
fallback_dns for failover, web UI on LAN, filters), manages the daemon
- dns/apply.uc: dns_main_mode (dnsmasq->AdGuard->sing-box chain, or AdGuard on
:53 with dnsmasq DHCP-only)
- settings: dns_main_mode (Main DNS) + dns_adguard_failover_enabled
- sections: routed_dns_type/dns_type 'adguard' resolve via the AdGuard provider
upstreams; validator accepts the new type
- system-info: adguard_version/installed/enabled/backup fields
Frontend:
- component card 'AdGuard Home' with enable/disable + version actions
- LuCI DNS settings tab: Main DNS selector and failover flag
- section.js: AdGuard Home routed DNS protocol option
Tests: tests/adguard_validator.sh, tests/adguard_runtime.sh