fix: P1 call-desk defects batch

- Mute persists across calls: sip-manager's "ended/failed" branch now
  resets the Recoil sipIsMutedAtom + sipIsOnHoldAtom (previously only
  the SIP track was unmuted, leaving the UI icon + toggle logic in a
  muted state that the next call inherited).
- Telephony-unavailable dial pad: call-desk.tsx dial-pad "Call" button
  was missing an isRegistered check in its disabled prop, so it stayed
  clickable when SIP was down. Button now shows "Telephony unavailable"
  and is disabled.
- Past dates in Follow-up: enquiry-form's follow-up date input had no
  min constraint. Switched to a raw <input type="date"> with min set
  to today's ISO date.
- Returning-patient AI summary during call: ai-chat-panel now auto-fires
  a "give me a quick summary of <caller>" request whenever the caller's
  leadId changes (new incoming call). Clears prior chat state so each
  caller starts fresh.
- Remove Type column in Patients page (Badge import also pruned).

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

src/pages/call-desk.tsx

@@ -19,7 +19,7 @@ import { cx } from '@/utils/cx';
 export const CallDeskPage = () => {
     const { user } = useAuth();
     const { leadActivities, calls, followUps: dataFollowUps, patients, appointments } = useData();
-    const { callState, callerNumber, callUcid, dialOutbound } = useSip();
+    const { callState, callerNumber, callUcid, dialOutbound, isRegistered } = useSip();
     const { missedCalls, followUps, marketingLeads, loading } = useWorklist();
     const [selectedLead, setSelectedLead] = useState<WorklistLead | null>(null);
     const [contextOpen, setContextOpen] = useState(true);
@@ -204,11 +204,11 @@ export const CallDeskPage = () => {
                                     </div>
                                     <button
                                         onClick={handleDial}
-                                        disabled={dialling || dialNumber.replace(/[^0-9]/g, '').length < 10}
+                                        disabled={!isRegistered || dialling || dialNumber.replace(/[^0-9]/g, '').length < 10}
                                         className="w-full flex items-center justify-center gap-2 rounded-lg bg-success-solid py-2.5 text-sm font-medium text-white hover:opacity-90 disabled:bg-disabled disabled:cursor-not-allowed transition duration-100 ease-linear"
                                     >
                                         <FontAwesomeIcon icon={faPhone} className="size-3.5" />
-                                        {dialling ? 'Dialling...' : 'Call'}
+                                        {dialling ? 'Dialling...' : !isRegistered ? 'Telephony unavailable' : 'Call'}
                                     </button>
                                 </div>
                             )}