feat: enhance new-patient AI chat flow with full scheduling and eligibility

- Add 3-message intro (self-intro → empathetic ack → new/existing question) via single TwiML response to guarantee delivery order
- Detect reschedule intent from first message; look up existing appointment date
- New patient flow: ask insurance type → MassHealth consent → member ID + DOB → Selenium eligibility check
- Post-eligibility: active → ask appointment date/time with office-hours validation; inactive → ask other insurance or collect contact info
- Date/time collection mirrors reschedule flow: check office day open, ask time, validate against office hours
- Auto-create appointment in schedule for known patients on confirmation; use first available staff member
- Add openPhoneReply toggle (Settings → AI Chat) to respond to any number at any time
- Add 5-minute inactivity timeout: reset conversation to initial stage and clear pending state
- Normalize MassHealth DOB to zero-padded MM/DD/YYYY before Selenium submission
- Expand isExistingPatient classifier to recognize "old patient", "old", "previous", "prior"
- Existing patient confirmation message now acknowledges patient type before asking about insurance

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/Backend/src/routes/ai-settings.ts

@@ -12,7 +12,11 @@ router.get("/settings", async (req: Request, res: Response): Promise<any> => {
     const settings = await storage.getAiSettings(userId);
     if (!settings) return res.status(200).json(null);
 
-    return res.status(200).json({ id: settings.id, apiKey: settings.apiKey });
+    return res.status(200).json({
+      id:             settings.id,
+      apiKey:         settings.apiKey,
+      openPhoneReply: settings.openPhoneReply ?? false,
+    });
   } catch (err) {
     return res.status(500).json({ error: "Failed to fetch AI settings", details: String(err) });
   }
@@ -36,6 +40,37 @@ router.put("/settings", async (req: Request, res: Response): Promise<any> => {
   }
 });
 
+// GET /api/ai/advanced-settings
+router.get("/advanced-settings", async (req: Request, res: Response): Promise<any> => {
+  try {
+    const userId = req.user?.id;
+    if (!userId) return res.status(401).json({ message: "Unauthorized" });
+
+    const openPhoneReply = await storage.getOpenPhoneReply(userId);
+    return res.status(200).json({ openPhoneReply });
+  } catch (err) {
+    return res.status(500).json({ error: "Failed to fetch advanced settings", details: String(err) });
+  }
+});
+
+// PUT /api/ai/advanced-settings
+router.put("/advanced-settings", async (req: Request, res: Response): Promise<any> => {
+  try {
+    const userId = req.user?.id;
+    if (!userId) return res.status(401).json({ message: "Unauthorized" });
+
+    const { openPhoneReply } = req.body;
+    if (typeof openPhoneReply !== "boolean") {
+      return res.status(400).json({ message: "openPhoneReply must be a boolean" });
+    }
+
+    await storage.setOpenPhoneReply(userId, openPhoneReply);
+    return res.status(200).json({ openPhoneReply });
+  } catch (err) {
+    return res.status(500).json({ error: "Failed to save advanced settings", details: String(err) });
+  }
+});
+
 // GET /api/ai/chat-templates
 router.get("/chat-templates", async (req: Request, res: Response): Promise<any> => {
   try {