feat: add Deltains claim submission flow

Adds a full "Deltains Claim" button next to Delta MA Claim, mirroring
the DDMA claim flow across frontend, backend queue/routes, and a new
Selenium worker. Reuses the existing Deltains eligibility login/OTP
code and was iteratively wired against the live portal (patient roster
search, per-service-line fields, tooth number/surface selects, review
and submit). Also fixes chatbot/insurance-alias carrier recognition so
"deltains" resolves correctly instead of falling back to MassHealth.

apps/Backend/src/services/seleniumDeltainsClaimClient.ts

@@ -0,0 +1,35 @@
+import axios from "axios";
+
+const SELENIUM_BASE = process.env.SELENIUM_SERVICE_URL ?? "http://localhost:5002";
+
+/**
+ * POST /deltains-claim
+ * Returns { status: "started", session_id: "<uuid>" }
+ */
+export async function forwardToSeleniumDeltainsClaimAgent(
+  data: Record<string, any>
+): Promise<{ status: string; session_id: string }> {
+  const resp = await axios.post(`${SELENIUM_BASE}/deltains-claim`, data);
+  return resp.data;
+}
+
+/**
+ * GET /session/{sid}/status
+ */
+export async function getSeleniumDeltainsClaimSessionStatus(
+  sessionId: string
+): Promise<Record<string, any>> {
+  const resp = await axios.get(`${SELENIUM_BASE}/session/${sessionId}/status`);
+  return resp.data;
+}
+
+/**
+ * POST /session/{sid}/submit-otp
+ */
+export async function forwardOtpToSeleniumDeltainsClaimAgent(
+  sessionId: string,
+  otp: string
+): Promise<Record<string, any>> {
+  const resp = await axios.post(`${SELENIUM_BASE}/submit-otp`, { session_id: sessionId, otp });
+  return resp.data;
+}