refactor: remove direct DNS mode

agent/README.md

@@ -1,8 +1,7 @@
 # OpenWrt RMM Agent
 
-Current stable Go agent: `0.6.0`. It reports runtime health, pending command results,
-the last heartbeat transport error after connectivity is restored, and optionally keeps
-the router's direct DNS addresses current.
+Current stable Go agent: `0.6.1`. It reports runtime health, pending command results,
+and the last heartbeat transport error after connectivity is restored.
 
 Production Go agent for OpenWrt, with the shell implementation retained as a fallback runtime.
 
@@ -29,10 +28,6 @@ SERVER_URL="https://rmm.example.com"
 ENROLLMENT_TOKEN="paste-a-one-time-grant-from-your-account"
 INTERVAL_SECONDS="30"
 TUNNEL_IDENTITY_FILE="/etc/rmm-agent/tunnel_key"
-DIRECT_DNS_ENABLED="false"
-DNS_UPDATE_INTERVAL_SECONDS="300"
-PUBLIC_IPV4_URL="https://api.ipify.org"
-PUBLIC_IPV6_URL="https://api6.ipify.org"
 ```
 
 After enrollment the agent writes:
@@ -84,19 +79,6 @@ The Go agent is available as the production OpenWrt package and supports the mig
 
 Other queued commands are reported as failed with a clear message.
 
-### Direct DNS updates
-
-Direct DNS reporting is opt-in. When enabled, the agent queries the configured HTTPS
-endpoints in parallel, validates that their responses are public IPv4/IPv6 addresses, and
-sends the complete address state through `/api/agent/dns/update` using its existing device
-token. A successful update is refreshed every five minutes by default; failures retry after
-one minute and do not make the main heartbeat unhealthy.
-
-The default discovery endpoints are operated by ipify. Clear the IPv6 URL on routers without
-public IPv6, or replace either endpoint with trusted HTTPS services under your control. The
-agent refuses HTTP URLs, embedded URL credentials, redirects, oversized responses, and
-private or reserved addresses.
-
 Build locally:
 
 ```sh