fix: use sips scheme in From/Contact when forwarding to a sips Request-URI

RFC 3261 8.1.1.8 requires a SIPS Contact when the Request-URI is SIPS.
The forward path (dial verb to a sip target) always defaulted to sip:.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/call-session.js

@@ -505,17 +505,21 @@ class CallSession extends Emitter {
         }
         else {
           const uri = parseUri(this.req.uri);
+          /* RFC 3261 8.1.1.8: a sips Request-URI requires a sips Contact */
+          const scheme = uri.scheme === 'sips' ? 'sips' : 'sip';
           hdrs = {
             ...hdrs,
             'From': createBLegFromHeader({
               logger: this.logger,
               req: this.req,
+              scheme,
               transport: uri.params.transport,
               ...(private_network && {host: this.privateSipAddress})
             }),
             'Contact': createBLegFromHeader({
               logger: this.logger,
               req: this.req,
+              scheme,
               transport: uri.params.transport,
               ...(private_network && {host: this.privateSipAddress})
             })

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "sbc-outbound",
-  "version": "0.9.10",
+  "version": "0.9.11",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "sbc-outbound",
-      "version": "0.9.10",
+      "version": "0.9.11",
       "license": "MIT",
       "dependencies": {
         "@babel/helpers": "^7.26.10",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sbc-outbound",
-  "version": "0.9.10",
+  "version": "0.9.11",
   "main": "app.js",
   "engines": {
     "node": ">= 20.0.0"