feat(config): add Ozonetel admin credential fields to telephony form

Admin username + password inputs in the Ozonetel section for supervisor
barge/whisper/listen access. Follows existing masked password pattern.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/forms/telephony-form.tsx

@@ -17,6 +17,8 @@ export type TelephonyFormValues = {
         did: string;
         sipId: string;
         campaignName: string;
+        adminUsername: string;
+        adminPassword: string;
     };
     sip: {
         domain: string;
@@ -37,6 +39,8 @@ export const emptyTelephonyFormValues = (): TelephonyFormValues => ({
         did: '',
         sipId: '',
         campaignName: '',
+        adminUsername: '',
+        adminPassword: '',
     },
     sip: {
         domain: 'blr-pub-rtc4.ozonetel.com',
@@ -108,6 +112,27 @@ export const TelephonyForm = ({ value, onChange }: TelephonyFormProps) => {
                     value={value.ozonetel.campaignName}
                     onChange={(v) => patchOzonetel({ campaignName: v })}
                 />
+                <div>
+                    <h4 className="mt-2 text-xs font-semibold text-secondary">Supervisor Access</h4>
+                    <p className="mt-0.5 text-xs text-tertiary">
+                        Ozonetel portal admin credentials — required for supervisor barge/whisper/listen.
+                    </p>
+                </div>
+                <div className="grid grid-cols-2 gap-3">
+                    <Input
+                        label="Admin username"
+                        placeholder="Ozonetel portal admin login"
+                        value={value.ozonetel.adminUsername}
+                        onChange={(v) => patchOzonetel({ adminUsername: v })}
+                    />
+                    <Input
+                        label="Admin password"
+                        type="password"
+                        placeholder="Leave '***masked***' to keep current"
+                        value={value.ozonetel.adminPassword}
+                        onChange={(v) => patchOzonetel({ adminPassword: v })}
+                    />
+                </div>
             </section>
 
             <section className="flex flex-col gap-4">