Replace hand-edited JSON with a setup wizard

Melissa had to author entity.json by hand and know FTPS from SFTP to do
it - which is what broke the last two CAMBS runs. setup-entity.bat now
asks the questions and writes the file:

- protocol is a numbered menu, stored as an explicit "protocol" key that
  wins over the sftp:// host prefix and the older tls flag
- pasted schemes and paths are stripped off the host before saving
- it creates the practice folders, then logs in and checks every
  practice's remote folder exists, so a wrong path or protocol surfaces
  in seconds instead of in the next morning's run

Also drops insurance_file_type from the required path: with no setting
the engine sends every file in the date folder minus Windows clutter, so
"No .pdf files" can't happen on a folder full of TIFs. Connection
failures now print what to change rather than just WinSCP's wording.

Entities/EXAMPLE/entity.json

@@ -1,11 +1,11 @@
 {
+  "_note": "You do not have to write this by hand - double-click setup-entity.bat and it asks you the questions instead. The 'ftps' section is the daily date-folder upload (over whatever protocol says, SFTP included); the 'sftp' section is the patient files.",
   "workflow": "insurance+patient",
-  "insurance_file_type": "pdf",
 
   "ftps": {
     "host": "ftp.example.com",
-    "port": 21,
-    "tls": true,
+    "protocol": "ftps",
+    "port": null,
     "username": "shared-username",
     "password": "shared-password",
     "tiff_path": "/{practice}/Insurance",
@@ -14,7 +14,8 @@
 
   "sftp": {
     "host": "sftp.example.com",
-    "port": 22,
+    "protocol": "sftp",
+    "port": null,
     "username": "shared-username",
     "password": "shared-password",
     "patient_path": "/{practice}/Patient"