feat(routing): require explicit inbound DID routes and normalize SIP identities for provider-based number matching

rust/crates/proxy-engine/src/sip_leg.rs

@@ -128,17 +128,24 @@ impl SipLeg {
                 max_forwards: Some(70),
                 body: Some(sdp),
                 content_type: Some("application/sdp".to_string()),
-                extra_headers: Some(vec![
-                    ("User-Agent".to_string(), "SipRouter/1.0".to_string()),
-                ]),
+                extra_headers: Some(vec![(
+                    "User-Agent".to_string(),
+                    "SipRouter/1.0".to_string(),
+                )]),
             },
         );
 
-        self.dialog = Some(SipDialog::from_uac_invite(&invite, ip, self.config.lan_port));
+        self.dialog = Some(SipDialog::from_uac_invite(
+            &invite,
+            ip,
+            self.config.lan_port,
+        ));
         self.invite = Some(invite.clone());
         self.state = LegState::Inviting;
 
-        let _ = socket.send_to(&invite.serialize(), self.config.sip_target).await;
+        let _ = socket
+            .send_to(&invite.serialize(), self.config.sip_target)
+            .await;
     }
 
     /// Handle an incoming SIP message routed to this leg.
@@ -443,10 +450,7 @@ pub enum SipLegAction {
 /// Build an ACK for a non-2xx response (same transaction as the INVITE).
 fn build_non_2xx_ack(original_invite: &SipMessage, response: &SipMessage) -> SipMessage {
     let via = original_invite.get_header("Via").unwrap_or("").to_string();
-    let from = original_invite
-        .get_header("From")
-        .unwrap_or("")
-        .to_string();
+    let from = original_invite.get_header("From").unwrap_or("").to_string();
     let to = response.get_header("To").unwrap_or("").to_string();
     let call_id = original_invite.call_id().to_string();
     let cseq_num: u32 = original_invite