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/pages/doctor.dart

@@ -4,6 +4,7 @@ import 'package:flutter/services.dart';
 import '../data/error_presentation.dart';
 import '../data/chain_log.dart';
 import '../data/hub.dart';
+import '../data/hub_auth_token.dart';
 import '../data/system_actions.dart';
 import '../l10n/app_localizations.dart';
 import '../theme/theme.dart';
@@ -334,6 +335,24 @@ class _EventLogPanel extends StatelessWidget {
   }
 }
 
+/// True when [path] points into an OS-managed temporary
+/// directory (macOS `/var/folders`, Unix `/tmp`, the Windows
+/// user/system temp folders) — locations the OS may clean up
+/// at any time. The doctor page warns when the audit DB lives
+/// in one: an evidence log the OS can silently delete is not
+/// evidence. Top-level so the unit test can exercise the
+/// classification directly.
+bool isVolatilePath(String path) {
+  if (path.isEmpty) return false;
+  final p = path.toLowerCase().replaceAll('\\', '/');
+  return p.startsWith('/tmp/') ||
+      p.startsWith('/private/tmp/') ||
+      p.startsWith('/var/folders/') ||
+      p.startsWith('/private/var/folders/') ||
+      p.contains('/appdata/local/temp/') ||
+      p.contains('/windows/temp/');
+}
+
 /// Lists the daemon's filesystem paths with one "Open" button
 /// per row. Windows operators who never touch a shell still
 /// need a way to inspect the audit DB or edit the operator
@@ -374,10 +393,33 @@ class _DaemonPathsPanel extends StatelessWidget {
       );
     }
 
+    final theme = Theme.of(context);
     return ChainCard(
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
+          if (isVolatilePath(paths.dbPath)) ...[
+            Row(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                const Icon(
+                  Icons.warning_amber_outlined,
+                  size: 16,
+                  color: ChainColors.warning,
+                ),
+                const SizedBox(width: ChainSpace.sm),
+                Expanded(
+                  child: Text(
+                    l.doctorDbVolatileWarning,
+                    style: theme.textTheme.bodySmall?.copyWith(
+                      color: theme.colorScheme.onSurfaceVariant,
+                    ),
+                  ),
+                ),
+              ],
+            ),
+            const SizedBox(height: ChainSpace.sm),
+          ],
           for (final e in entries)
             _PathRow(label: e.$1, path: e.$2, icon: e.$3, isDirectory: e.$4),
         ],
@@ -512,10 +554,20 @@ class _DaemonActionsCardState extends State<_DaemonActionsCard> {
   bool _binaryMissing = false;
   ChannelStatusSnapshot? _channels;
 
+  /// Trimmed length of `~/.chain/hub-auth-token`, or null when
+  /// Studio talks to the hub anonymously. Length only — the
+  /// secret itself never reaches the UI.
+  int? _tokenChars;
+
   @override
   void initState() {
     super.initState();
     _refreshStatus();
+    HubAuthToken.charCount()
+        .then((n) {
+          if (mounted) setState(() => _tokenChars = n);
+        })
+        .catchError((_) {});
   }
 
   Future<void> _refreshStatus() async {
@@ -528,6 +580,21 @@ class _DaemonActionsCardState extends State<_DaemonActionsCard> {
     }
   }
 
+  String _connectionLine(AppLocalizations l) {
+    final ep = HubService.instance.currentEndpoint;
+    final isLocal =
+        ep.host == '127.0.0.1' || ep.host == 'localhost' || ep.host == '::1';
+    final transport = ep.secure
+        ? l.doctorConnTls
+        : isLocal
+        ? l.doctorConnPlainLocal
+        : l.doctorConnPlainRemote;
+    final auth = _tokenChars == null
+        ? l.doctorConnAnonymous
+        : l.doctorConnToken(_tokenChars!);
+    return l.doctorConnLine(ep.toString(), transport, auth);
+  }
+
   Future<void> _run(
     String label,
     Future<({bool ok, String stdout, String stderr})> Function() action,
@@ -626,6 +693,17 @@ class _DaemonActionsCardState extends State<_DaemonActionsCard> {
                 color: theme.colorScheme.onSurfaceVariant,
               ),
             ),
+            const SizedBox(height: 2),
+            // Who-talks-to-whom-how in one line: endpoint,
+            // transport security, and whether a bearer token is
+            // attached — the auditor's baseline questions the
+            // green "connected" dot alone cannot answer.
+            SelectableText(
+              _connectionLine(l),
+              style: theme.textTheme.bodySmall?.copyWith(
+                color: theme.colorScheme.onSurfaceVariant,
+              ),
+            ),
             const SizedBox(height: ChainSpace.md),
             Wrap(
               spacing: ChainSpace.sm,