feat: add United Ucard claim worker and fix batch-column site-key routing

Adds a "United Ucard Claim" button (claims/preauth insurance form) that
submits through a full Selenium pipeline mirroring the Tufts SCO claim
worker: frontend handler -> backend route/queue processor -> Python
agent, reusing the persistent login/OTP session from the existing
United Ucard eligibility check. Implements the UHC Dental claim wizard
end-to-end (Provider Information, Patient Information search/select,
Claim Information procedures + questions, Upload Documents, Review and
Sign, Submit); the final confirmation-page PDF/claim-number capture is
still a TODO stub pending that page's DOM.

Also wires United Ucard into the AI chatbot's eligibility flow
(insuranceAliases.json, siteKeyToAutoCheck, clarification options), and
fixes a bug where the AI-column batch claim feature silently defaulted
United Ucard patients to MassHealth because batchColumnDeriveSiteKey
had no matching branch and no job-dispatch case for UNITED_UCARD.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/Backend/src/services/seleniumUnitedUcardClaimClient.ts

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