feat: wire Tufts SCO to DentaQuest portal and fix insurance credential dropdown

- Add /dentaquest-eligibility endpoint in Python agent (Tufts SCO uses providers.dentaquest.com)
- Add backend route, processor, and service client for Tufts SCO (separate from UnitedSCO/DentalHub)
- Fix Tufts SCO button to post to new tuftssco route instead of unitedsco
- Fix credential field names: dentaquestUsername/Password (was tuftsscoUsername/Password)
- Fix socket event: listen for selenium:dentaquest_session_started (was unitedsco)
- Fix error visibility: keep session alive 30s on error so backend reads real message
- Replace free-text Site Key field with dropdown to prevent key mismatches

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

apps/SeleniumService/selenium_DDMA_eligibilityCheckWorker.py

@@ -335,32 +335,6 @@ class AutomationDeltaDentalMAEligibilityCheck:
                 except Exception as e:
                     print(f"[DDMA step1] Warning: Could not fill DOB: {e}")
 
-            # 3. Fill First Name if provided
-            if self.firstName:
-                try:
-                    first_name_input = wait.until(EC.presence_of_element_located(
-                        (By.XPATH, '//input[@placeholder="First name - 1 char minimum" or contains(@placeholder,"first name") or contains(@name,"firstName")]')
-                    ))
-                    first_name_input.clear()
-                    first_name_input.send_keys(self.firstName)
-                    print(f"[DDMA step1] Entered First Name: {self.firstName}")
-                    time.sleep(0.2)
-                except Exception as e:
-                    print(f"[DDMA step1] Warning: Could not fill First Name: {e}")
-
-            # 4. Fill Last Name if provided
-            if self.lastName:
-                try:
-                    last_name_input = wait.until(EC.presence_of_element_located(
-                        (By.XPATH, '//input[@placeholder="Last name - 2 char minimum" or contains(@placeholder,"last name") or contains(@name,"lastName")]')
-                    ))
-                    last_name_input.clear()
-                    last_name_input.send_keys(self.lastName)
-                    print(f"[DDMA step1] Entered Last Name: {self.lastName}")
-                    time.sleep(0.2)
-                except Exception as e:
-                    print(f"[DDMA step1] Warning: Could not fill Last Name: {e}")
-
             time.sleep(0.3)
 
             # Click Search button