feat(store,doctor): surface the hub's trust + exposure data (0.77.0)

The trust-gate dialog replaces its generic 'no per-entry status yet
(alpha)' note with the hub's classified verification statement —
pinned store key / trusted publishers (green), installs without
signature checking (amber), install would be refused (red), bridge
entry (neutral) — via one shared describeInstallVerification mapping.
Against a pre-0.23 hub the field is empty and the old honest wording
stays (pinned by test).

Information architecture: policy-off is a GLOBAL fact, so it appears
as ONE ChainInlineHelp notice above the store grid instead of a
warning pill on every card (card noise); only 'blocked' — a genuine
per-source anomaly — earns a card pill. Doctor's host services show
the hub-classified network reach per endpoint (local only / private
network / publicly reachable with a protect-it hint / reach unknown).

Verified end-to-end against the live dev hub (guide harness): the
wire field arrives, the store page shows exactly one policy notice
and quiet cards; trust-gate variants captured via the dialog
harness. Suite 123 green.

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

lib/data/hub.dart

@@ -937,6 +937,7 @@ class HubService {
             source: e.source,
             canonicalCategory: e.canonicalCategory,
             canonicalCategoryLabel: e.canonicalCategoryLabel,
+            installVerification: e.installVerification,
           ),
         )
         .toList();
@@ -1289,7 +1290,12 @@ class HubService {
       services: services
           .map(
             (s) =>
-                ServiceEntry(name: s.name, endpoint: s.endpoint, tags: s.tags),
+                ServiceEntry(
+              name: s.name,
+              endpoint: s.endpoint,
+              tags: s.tags,
+              exposure: s.exposure,
+            ),
           )
           .toList(),
       update: UpdateStatus(
@@ -1386,10 +1392,16 @@ class ServiceEntry {
   final String endpoint;
   final List<String> tags;
 
+  /// Network reach of [endpoint] as classified by the hub
+  /// (host part only, no DNS): "loopback" / "private" / "public" /
+  /// "unknown". Empty from pre-0.23 hubs.
+  final String exposure;
+
   const ServiceEntry({
     required this.name,
     required this.endpoint,
     required this.tags,
+    this.exposure = '',
   });
 }
 
@@ -2233,6 +2245,15 @@ class StoreItem {
   /// Human-readable label for [canonicalCategory] (e.g. "Data & Formats").
   final String canonicalCategoryLabel;
 
+  /// How an install of this entry would be verified under the
+  /// hub's CURRENT policy — computed hub-side with the same
+  /// resolvers the install gate enforces, so this can never
+  /// disagree with what actually happens:
+  /// "pinned-key" / "trusted-publishers" / "unverified" /
+  /// "blocked" / "federated". Empty from pre-0.23 hubs — the UI
+  /// keeps its generic note then.
+  final String installVerification;
+
   /// True iff this entry is a Studio plugin/theme rather than a flow
   /// module — drives the "Modules | Studio & Themes" store segment.
   bool get isStudioPlugin => canonicalCategory == 'studio-themes';
@@ -2264,5 +2285,6 @@ class StoreItem {
     this.source = '',
     this.canonicalCategory = '',
     this.canonicalCategoryLabel = '',
+    this.installVerification = '',
   });
 }