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.

setup-entity.bat

@@ -0,0 +1,4 @@
+@echo off
+REM Asks a few questions and writes the settings files - no JSON editing.
+powershell.exe -ExecutionPolicy Bypass -File "%~dp0Setup-Entity.ps1"
+pause