feat: add internal AI chat assistant and AI Input Agent page

- Add Gemini-powered internal staff chatbot (free-text input in the
  upper-right bot panel): type "check MARIA GONZALES" to search patient
  and pre-fill eligibility, or "open claims" to navigate directly
- Add /api/ai/internal-chat endpoint with LangGraph + Google Gemini
  classifier (intent: check_eligibility, find_patient, navigate_*)
- Add Users AI Chat settings section in Settings > Advanced > AI Chat
  to configure a custom system prompt for the internal assistant
- Store internal chat system prompt in existing twilioSettings JSON
  blob (no DB migration needed)
- Add AI Input Agent sidebar entry and placeholder page describing
  planned keyboard-automation typing into Open Dental / Eaglesoft

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

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

@@ -1,5 +1,6 @@
 import express, { Request, Response } from "express";
 import { storage } from "../storage";
+import { classifyInternalChat } from "../ai/internal-chat-graph";
 
 const router = express.Router();
 
@@ -97,4 +98,152 @@ router.put("/chat-templates", async (req: Request, res: Response): Promise<any>
   }
 });
 
+// GET /api/ai/internal-chat-settings
+router.get("/internal-chat-settings", async (req: Request, res: Response): Promise<any> => {
+  try {
+    const userId = req.user?.id;
+    if (!userId) return res.status(401).json({ message: "Unauthorized" });
+    const systemPrompt = await storage.getInternalChatSystemPrompt(userId);
+    return res.status(200).json({ systemPrompt });
+  } catch (err) {
+    return res.status(500).json({ error: "Failed to fetch internal chat settings", details: String(err) });
+  }
+});
+
+// PUT /api/ai/internal-chat-settings
+router.put("/internal-chat-settings", async (req: Request, res: Response): Promise<any> => {
+  try {
+    const userId = req.user?.id;
+    if (!userId) return res.status(401).json({ message: "Unauthorized" });
+    const { systemPrompt } = req.body;
+    if (typeof systemPrompt !== "string") return res.status(400).json({ message: "systemPrompt must be a string" });
+    await storage.saveInternalChatSystemPrompt(userId, systemPrompt.trim());
+    return res.status(200).json({ systemPrompt: systemPrompt.trim() });
+  } catch (err) {
+    return res.status(500).json({ error: "Failed to save internal chat settings", details: String(err) });
+  }
+});
+
+// POST /api/ai/internal-chat
+router.post("/internal-chat", async (req: Request, res: Response): Promise<any> => {
+  try {
+    const userId = req.user?.id;
+    if (!userId) return res.status(401).json({ message: "Unauthorized" });
+
+    const { message } = req.body;
+    if (!message?.trim()) return res.status(400).json({ message: "message is required" });
+
+    const aiSettings = await storage.getAiSettings(userId);
+    if (!aiSettings?.apiKey) {
+      return res.status(200).json({
+        reply: "AI is not configured. Please add a Google AI API key in Settings.",
+      });
+    }
+
+    const extraSystemPrompt = await storage.getInternalChatSystemPrompt(userId);
+    const classification = await classifyInternalChat(message.trim(), aiSettings.apiKey, extraSystemPrompt || undefined);
+
+    // Handle navigation intents immediately
+    if (classification.intent === "navigate_claims") {
+      return res.status(200).json({ reply: classification.fallbackReply, action: "navigate", actionData: { url: "/claims" } });
+    }
+    if (classification.intent === "navigate_schedule") {
+      return res.status(200).json({ reply: classification.fallbackReply, action: "navigate", actionData: { url: "/appointments" } });
+    }
+
+    // Handle patient intents — search DB
+    if (classification.intent === "check_eligibility" || classification.intent === "find_patient") {
+      const name = classification.patientName?.trim();
+      if (!name) {
+        return res.status(200).json({ reply: "Please include the patient's name in your message." });
+      }
+
+      const patients = await storage.searchPatients({
+        filters: {
+          OR: [
+            { firstName: { contains: name, mode: "insensitive" } },
+            { lastName: { contains: name, mode: "insensitive" } },
+            {
+              AND: name.split(/\s+/).map((part: string) => ({
+                OR: [
+                  { firstName: { contains: part, mode: "insensitive" } },
+                  { lastName: { contains: part, mode: "insensitive" } },
+                ],
+              })),
+            },
+          ],
+        },
+        limit: 5,
+        offset: 0,
+      });
+
+      if (!patients || patients.length === 0) {
+        return res.status(200).json({
+          reply: `No patient found matching "${name}". Try a different spelling or search on the Patients page.`,
+        });
+      }
+
+      const patient = patients[0]!;
+      const fullName = `${patient.firstName ?? ""} ${patient.lastName ?? ""}`.trim();
+
+      if (classification.intent === "find_patient") {
+        const ins = patient.insuranceProvider ? ` · ${patient.insuranceProvider}` : "";
+        const id  = patient.insuranceId ? ` (ID: ${patient.insuranceId})` : "";
+        return res.status(200).json({
+          reply: `Found: ${fullName}${ins}${id}`,
+          action: "show_patient",
+          actionData: {
+            patient: {
+              id: patient.id,
+              firstName: patient.firstName,
+              lastName: patient.lastName,
+              insuranceId: patient.insuranceId ?? null,
+              insuranceProvider: patient.insuranceProvider ?? null,
+              dateOfBirth: patient.dateOfBirth ? patient.dateOfBirth.toISOString().split("T")[0] : null,
+            },
+          },
+        });
+      }
+
+      // check_eligibility
+      if (!patient.insuranceId) {
+        return res.status(200).json({
+          reply: `Found ${fullName} but no Member ID is on file. Please add their insurance info first.`,
+          action: "show_patient",
+          actionData: {
+            patient: {
+              id: patient.id,
+              firstName: patient.firstName,
+              lastName: patient.lastName,
+              insuranceId: null,
+              insuranceProvider: patient.insuranceProvider ?? null,
+              dateOfBirth: patient.dateOfBirth ? patient.dateOfBirth.toISOString().split("T")[0] : null,
+            },
+          },
+        });
+      }
+
+      return res.status(200).json({
+        reply: `Found ${fullName}. Ready to check eligibility.`,
+        action: "check_eligibility_prefill",
+        actionData: {
+          patient: {
+            id: patient.id,
+            firstName: patient.firstName,
+            lastName: patient.lastName,
+            insuranceId: patient.insuranceId,
+            insuranceProvider: patient.insuranceProvider ?? null,
+            dateOfBirth: patient.dateOfBirth ? patient.dateOfBirth.toISOString().split("T")[0] : null,
+          },
+        },
+      });
+    }
+
+    // General intent — return Gemini's reply
+    return res.status(200).json({ reply: classification.fallbackReply });
+  } catch (err) {
+    return res.status(500).json({ error: "Internal chat error", details: String(err) });
+  }
+});
+
 export default router;