fix(doctor): honest module count, temp-path audit warning, connection line

Three doctor-page findings from the usertest panel:

- Module tile no longer counts the hub's built-in 'system'
  pseudo-module — a fresh hub shows 0 modules, matching the
  welcome checklist's definition of an install. Counting is a
  top-level function with unit tests.
- When the audit DB lives in an OS-cleanable temp directory
  (/var/folders, /tmp, Windows Temp), the daemon-files panel
  says so instead of presenting the state as healthy. The
  classifier is a top-level function with unit tests.
- The daemon card states who-talks-to-whom-how in one line:
  endpoint, transport security (TLS / unencrypted-local /
  unencrypted), and whether a bearer token is attached (length
  only) — the auditor's baseline the green dot cannot answer.

Also syncs pubspec.yaml (0.70.0 -> 0.72.0) with kStudioVersion,
which had drifted to 0.71.0 while pubspec stayed behind.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/data/about_info.dart

@@ -4,7 +4,7 @@
 
 /// Studio's own build version. Bump on every UI release so the
 /// running app self-identifies.
-const String kStudioVersion = '0.71.0';
+const String kStudioVersion = '0.72.0';
 
 const String kProductName = 'Ch∆In Studio';
 const String kVendorName = 'Flemming.AI (F∆I)';