dialplan: build the dial string per contact; iOS Linphone's push params broke Dial

Its Contact holds pn-prid=...:voip&...:remote, and PJSIP_DIAL_CONTACTS passes that '&' through,
so Dial rejected the whole device list and the call dropped for every device of the user.
sp-sub-contacts walks the AOR's contacts, drops pn-* params and FILTERs the rest. call-test
registers a phone with such a Contact and checks it is rung.

apps/api/test/asterisk/pn-phone.mjs

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// A phone that registers like iOS Linphone: push params holding '&' in its Contact. Answers
+// qualify OPTIONS, prints the Request-URI of each INVITE ("INVITE <uri>") and turns it down (486),
+// so the real phone on the same extension takes the call. call-test.ts runs it.
+// Usage: node pn-phone.mjs <asterisk host> <user> <password>
+import { createHash, randomUUID } from 'node:crypto';
+import { createSocket } from 'node:dgram';
+import { lookup } from 'node:dns/promises';
+import { networkInterfaces } from 'node:os';
+
+const [astHost, user, pass] = process.argv.slice(2);
+const md5 = (s) => createHash('md5').update(s).digest('hex');
+const ast = (await lookup(astHost)).address;
+const me = Object.values(networkInterfaces())
+  .flat()
+  .find((i) => i.family === 'IPv4' && !i.internal).address;
+const PORT = 5080;
+const uri = `sip:${astHost}`;
+const callId = randomUUID();
+const tag = randomUUID().slice(0, 8);
+const contact =
+  `<sip:${user}@${me}:${PORT};pn-prid=AAAA1111:voip&bbbb2222:remote;pn-provider=apns;` +
+  `pn-param=ABCD1234.org.linphone.phone.voip&remote;x-test=keep-me>`;
+
+const sock = createSocket('udp4');
+const send = (msg) => sock.send(msg, 5060, ast);
+const register = (cseq, auth) =>
+  [
+    `REGISTER ${uri} SIP/2.0`,
+    `Via: SIP/2.0/UDP ${me}:${PORT};rport;branch=z9hG4bK${randomUUID().slice(0, 12)}`,
+    'Max-Forwards: 70',
+    `From: <sip:${user}@${astHost}>;tag=${tag}`,
+    `To: <sip:${user}@${astHost}>`,
+    `Call-ID: ${callId}`,
+    `CSeq: ${cseq} REGISTER`,
+    `Contact: ${contact}`,
+    'Expires: 300',
+    ...(auth ? [`Authorization: ${auth}`] : []),
+    'Content-Length: 0',
+    '',
+    '',
+  ].join('\r\n');
+
+/** A response to a request: its Via, From, Call-ID and CSeq, and a To tag. */
+const reply = (req, status) => {
+  const keep = req.split('\r\n').filter((l) => /^(Via|From|To|Call-ID|CSeq):/i.test(l));
+  const lines = keep.map((l) => (/^To:/i.test(l) && !/;tag=/.test(l) ? `${l};tag=${tag}` : l));
+  return [`SIP/2.0 ${status}`, ...lines, 'Content-Length: 0', '', ''].join('\r\n');
+};
+
+sock.on('message', (buf) => {
+  const msg = buf.toString();
+  const first = msg.split('\r\n')[0];
+  const challenge = /WWW-Authenticate: Digest (.*)/i.exec(msg)?.[1];
+  if (first.includes(' 401 ') && challenge) {
+    const p = Object.fromEntries(
+      [...challenge.matchAll(/(\w+)="?([^",]*)"?/g)].map((m) => [m[1], m[2]]),
+    );
+    const cnonce = randomUUID().slice(0, 8);
+    const ha1 = md5(`${user}:${p.realm}:${pass}`);
+    const ha2 = md5(`REGISTER:${uri}`);
+    const response = md5(`${ha1}:${p.nonce}:00000001:${cnonce}:auth:${ha2}`);
+    send(
+      register(
+        2,
+        `Digest username="${user}", realm="${p.realm}", nonce="${p.nonce}", uri="${uri}", ` +
+          `response="${response}", algorithm=MD5, qop=auth, nc=00000001, cnonce="${cnonce}"` +
+          (p.opaque ? `, opaque="${p.opaque}"` : ''),
+      ),
+    );
+  } else if (first.startsWith('SIP/2.0 ')) console.log(`REGISTER ${first}`);
+  else if (first.startsWith('OPTIONS ')) send(reply(msg, '200 OK'));
+  else if (first.startsWith('INVITE ')) {
+    console.log(first.split(' ').slice(0, 2).join(' '));
+    send(reply(msg, '486 Busy Here'));
+  }
+});
+sock.bind(PORT, () => send(register(1)));