generator: PJSIP transports, extension endpoints and rtp config

Golden cases empty, one-user, webrtc-disabled and hostile-names; each also
renders identically from shuffled input. pnpm test:asterisk boots the
asterisk image with every golden case and fails on a missing endpoint or
context or any ERROR log line (checked against a deliberately broken case).
On 24.0.0-rc2: 101 and 101-web load with every set_var.

Task: M2-T3

package.json

@@ -14,7 +14,8 @@
     "test": "vitest run",
     "lint": "eslint . && prettier --check .",
     "format": "prettier --write .",
-    "typecheck": "pnpm -r typecheck"
+    "typecheck": "pnpm -r typecheck",
+    "test:asterisk": "node apps/api/test/asterisk/load-golden.mjs"
   },
   "devDependencies": {
     "@eslint/js": "^10.0.1",