Correct two docs left describing SMS as ntfy push, not AMI delivery

services/sms-inbound.sh was rebuilt to deliver texts into Asterisk over AMI,
landing in the softphone's own thread, and ntfy was dropped from that path
entirely. Two pieces of prose written against the earlier design survived and
now contradict the working implementation:

- docs/anveo-direct-setup-guide.md still ended its "native Messages app"
  section with "Codes arrive as ntfy push notifications instead". The point
  of that section — no SIP client can write into Android Messages or iOS
  Messages — is unchanged, but the place texts actually land is Sipnetic's
  message thread.
- services/pstn-trunk.sh's generated README claimed inbound SMS "doesn't
  touch Asterisk at all" and set up ntfy notifications. It is now the exact
  opposite: sms-inbound reads this service's pstn-personal-dids.conf and
  pstn-groups.conf to resolve DID ownership, the same files the inbound-voice
  ring logic uses, which also makes install order matter — noted there now.

Documentation only; no behaviour change, and services/sms-inbound.sh is not
touched.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NAddJGE1G6eGaPzmScG5Vh

services/pstn-trunk.sh

@@ -2503,11 +2503,17 @@ Dashboard's Extensions tab, live, no restart needed.
 
 ## Receiving SMS on the trunk DID
 
-Not handled by this service — SMS and voice are configured separately at the
-provider, and inbound SMS doesn't touch Asterisk at all. \`sudo ./setup.sh
-sms-inbound\` sets up verification codes arriving as ntfy push notifications;
-see that service's README for the short-code and mobile-DID caveats that
-decide whether codes actually get through.
+Configured separately at the provider (voice and SMS are independent settings
+on an Anveo DID), then handled by \`sudo ./setup.sh sms-inbound\` — which
+reads THIS service's \`pstn-personal-dids.conf\`/\`pstn-groups.conf\` to work
+out which extension or Ring Group owns the destination DID, exactly as the
+inbound-voice ring logic above does, and delivers the text into Asterisk over
+AMI as a SIP MESSAGE. Install this service first; that one depends on these
+files existing.
+
+See that service's README for the short-code and mobile-DID caveats that
+decide whether codes actually get through, and for why outbound SMS isn't a
+path yet.
 
 ## Managing this from a web UI