initial commit — SIP B2BUA + WebRTC bridge with Rust codec engine

Full-featured SIP router with multi-provider trunking, browser softphone
via WebRTC, real-time Opus/G.722/PCM transcoding in Rust, RNNoise ML
noise suppression, Kokoro neural TTS announcements, and a Lit-based
web dashboard with live call monitoring and REST API.

ts/sip/rewrite.ts

@@ -0,0 +1,54 @@
+/**
+ * SIP URI and SDP body rewriting helpers.
+ */
+
+import type { IEndpoint } from './types.ts';
+
+const SIP_URI_RE = /(sips?:)([^@>;,\s]+@)?([^>;,\s:]+)(:\d+)?/g;
+
+/**
+ * Replaces the host:port in every `sip:` / `sips:` URI found in `value`.
+ */
+export function rewriteSipUri(value: string, host: string, port: number): string {
+  return value.replace(SIP_URI_RE, (_m, scheme: string, userpart?: string) =>
+    `${scheme}${userpart || ''}${host}:${port}`);
+}
+
+/**
+ * Rewrites the connection address (`c=`) and audio media port (`m=audio`)
+ * in an SDP body.  Returns the rewritten body together with the original
+ * endpoint that was replaced (if any).
+ */
+export function rewriteSdp(
+  body: string,
+  ip: string,
+  port: number,
+): { body: string; original: IEndpoint | null } {
+  let origAddr: string | null = null;
+  let origPort: number | null = null;
+
+  const out = body
+    .replace(/\r\n/g, '\n')
+    .split('\n')
+    .map((line) => {
+      if (line.startsWith('c=IN IP4 ')) {
+        origAddr = line.slice('c=IN IP4 '.length).trim();
+        return `c=IN IP4 ${ip}`;
+      }
+      if (line.startsWith('m=audio ')) {
+        const parts = line.split(' ');
+        if (parts.length >= 2) {
+          origPort = parseInt(parts[1], 10);
+          parts[1] = String(port);
+        }
+        return parts.join(' ');
+      }
+      return line;
+    })
+    .join('\r\n');
+
+  return {
+    body: out,
+    original: origAddr && origPort ? { address: origAddr, port: origPort } : null,
+  };
+}