feat: AI chatbot preauth intent, UnitedDH pre-auth improvements

- Add preauth intent to AI chatbot (classifier, workflow, frontend UI card)
- Auto-prefill preauth form with CDT codes, service date, and mapped prices
- Auto-trigger preauth Selenium handler by insurance siteKey (MH/Tufts/CCA/UnitedDH)
- Default tentative service date to today+3 for preauth (user didn't pick a date)
- Fix #number always means tooth number, distributes to all procedures in comma list
- Fix bare "post"/"pos" → D2954 (was matching D2955 via keyword scorer)
- UnitedDH pre-auth: fill procedure date with Ctrl+A to overwrite prefilled value
- UnitedDH pre-auth: select Location "Summit Dental Care" in step1 (same as billing entity)
- UnitedDH pre-auth: remove page refresh in step9 to preserve pre-auth number
- UnitedDH pre-auth: wait for table rows before extracting pre-auth number
- UnitedDH pre-auth/claim: explicit wait for Submit button after file upload (no sleep)

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

apps/Backend/src/ai/cdt-lookup.ts

@@ -167,6 +167,8 @@ const DIRECT_CODE_MAP: Record<string, string> = {
   // Core / post
   "core bu":                "D2950",
   "p/c":                    "D2954",
+  "post":                   "D2954",
+  "pos":                    "D2954",
   "post core":              "D2954",
   // Crowns
   "recement":               "D2920",

apps/Backend/src/ai/internal-chat-graph.ts

@@ -9,6 +9,7 @@ export type InternalChatIntent =
   | "find_patient"          // look up patient record only
   | "schedule_appointment"  // add patient to today's (or specified) schedule
   | "claim_only"            // submit claim for procedures (no eligibility check)
+  | "preauth"               // submit pre-authorization for procedures
   | "navigate_claims"
   | "navigate_schedule"
   | "navigate_eligibility"
@@ -83,6 +84,11 @@ Intents:
                           e.g. "claim perio exam, 2BW for John Smith"
                           Use this when no eligibility check is requested — just billing/claiming services
                           Always extract appointmentDate when a date or "today" is mentioned
+- preauth               : submit a pre-authorization request for procedures
+                          e.g. "preauth rct, post, crown for John Smith"
+                          e.g. "pre auth #20 rct, post, crown for Zhiyuan Chen"
+                          e.g. "pre-auth D3320, D2952, D2740 for Maria"
+                          Use this when the user says "preauth", "pre auth", "pre-auth", or "prior auth"
 - navigate_claims       : open the claims page
 - navigate_schedule     : open the appointments/schedule page
 - navigate_eligibility  : open the insurance eligibility page
@@ -99,8 +105,12 @@ Rules:
   Only include actual clinical procedures in procedureNames.
 - For composite fillings with a tooth number, preserve the EXACT notation including tooth# and surfaces:
   e.g. "composite #29 O", "#8 MO", "composite #11 MOD" — keep the #number and surface letters together as one entry
+- #number always means a TOOTH number (never a case or pre-auth reference). When a single #number appears before a comma-separated list of procedures, apply it to EVERY procedure in the list.
+  e.g. "#20 rct, post, crown" → ["#20 rct", "#20 post", "#20 crown"]
+  e.g. "preauth #20 rct, pos, crown" → ["#20 rct", "#20 pos", "#20 crown"]
+  e.g. "#14 rct, buildup, crown" → ["#14 rct", "#14 buildup", "#14 crown"]
 - For RCT/root canal with a tooth number, preserve the tooth# in the entry:
-  e.g. "rct #29", "#14 root canal", "rct #6" — keep the #number with the procedure so the correct code can be selected
+  e.g. "rct #29", "#14 root canal", "rct #6", "#20 rct" — keep the #number with the procedure so the correct code can be selected
 - For SRP with a quadrant abbreviation (UL, UR, LL, LR), keep the code and quadrant together as one entry:
   e.g. "D4341 UL", "4341 LR", "D4342 UR" — the quadrant always travels with the SRP code
 - For multiple PA X-rays with tooth numbers, expand each PA into its own entry:

apps/Backend/src/ai/internal-chat-workflow.ts

@@ -49,6 +49,7 @@ export interface ChatResponse {
     | "need_insurance_clarification"
     | "appointment_created"
     | "claim_only_ready"
+    | "preauth_ready"
     | "need_appointment_selection"
     | "need_cdt_clarification";
   actionData?: Record<string, any>;
@@ -325,6 +326,12 @@ export async function runInternalChatWorkflow(
     return await handleClaimOnly(classification, storage, customAliases);
   }
 
+  // ── Pre-authorization ──────────────────────────────────────────────────────
+
+  if (intent === "preauth") {
+    return await handlePreauth(classification, storage, customAliases);
+  }
+
   // ── Schedule appointment ───────────────────────────────────────────────────
 
   if (intent === "schedule_appointment") {
@@ -692,6 +699,70 @@ async function handleClaimOnly(
   };
 }
 
+// ─── preauth ──────────────────────────────────────────────────────────────────
+
+async function handlePreauth(
+  c: ChatClassification,
+  storage: StorageLike,
+  customAliases: { phrase: string; cdtCode: string }[]
+): Promise<ChatResponse> {
+  let patient: ResolvedPatient | null = null;
+
+  if (c.memberId?.trim()) {
+    const existing = await findPatientByMemberId(c.memberId.trim(), c.dob, storage);
+    if (existing) patient = patientToResult(existing);
+  } else if (c.patientName?.trim()) {
+    const raw = await findPatientByName(c.patientName.trim(), storage);
+    if (raw) patient = patientToResult(raw);
+  }
+
+  if (!patient) {
+    return { reply: "Please include a patient name or Member ID so I can look them up." };
+  }
+
+  const procedureNames = stripAttachmentRefs(c.procedureNames ?? []);
+  if (procedureNames.length === 0) {
+    return { reply: "Please specify which procedures to pre-authorize (e.g. rct, post, crown)." };
+  }
+
+  const cdtResults = lookupCdtCodes(procedureNames, customAliases);
+  const matched = cdtResults.filter((r) => r.code !== null);
+  const unmatched = cdtResults.filter((r) => r.code === null);
+
+  if (unmatched.length > 0) {
+    const phrases = unmatched.map((r) => r.input);
+    return {
+      reply: `I don't recognize ${phrases.map((p) => `"${p}"`).join(", ")}. What CDT code${phrases.length > 1 ? "s are" : " is"} ${phrases.length > 1 ? "they" : "it"}? (e.g. D3320)`,
+      action: "need_cdt_clarification",
+      actionData: { unknownPhrases: phrases, matchedSoFar: matched.map((r) => ({ code: r.code!, description: r.description })) },
+    };
+  }
+
+  // Use explicit date from message; otherwise today+3 (pre-auth is for a future appointment)
+  let serviceDate: string = c.appointmentDate ?? (() => {
+    const d = new Date();
+    d.setDate(d.getDate() + 3);
+    return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}-${String(d.getDate()).padStart(2, "0")}`;
+  })();
+
+  const siteKey = resolveSiteKey(patient.insuranceProvider ?? null, c.insuranceHint ?? null) ?? "MH";
+  const fullName = `${patient.firstName ?? ""} ${patient.lastName ?? ""}`.trim();
+  const [sy, sm, sd] = serviceDate.split("-");
+  const dateLabel = `${sm}/${sd}/${sy}`;
+
+  return {
+    reply: `Opening pre-auth for ${fullName} (tentative date ${dateLabel}): ${matched.map((r) => `${r.code} (${r.description})`).join(", ")}.`,
+    action: "preauth_ready",
+    actionData: {
+      patient,
+      siteKey,
+      serviceDate,
+      matchedCodes: matched.map((r) => ({ code: r.code!, description: r.description, toothNumber: r.toothNumber, toothSurface: r.toothSurface, quad: r.quad })),
+      renderingProvider: c.renderingProvider ?? null,
+    },
+  };
+}
+
 // ─── schedule_appointment ─────────────────────────────────────────────────────
 
 const DEFAULT_STAFF_ID = 1; // Column A