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/install_verification.dart

@@ -0,0 +1,65 @@
+// Presentation of `StoreItem.installVerification` — the hub's
+// per-entry statement of how an install would be verified under
+// the CURRENT policy (computed hub-side with the same resolvers
+// the install gate enforces). One mapping, used by the trust-gate
+// dialog, the module detail sheet and the store card, so every
+// surface tells the same story.
+
+import '../l10n/app_localizations.dart';
+
+enum VerificationTone { good, neutral, warning, danger }
+
+class InstallVerificationInfo {
+  final String label;
+  final String body;
+  final VerificationTone tone;
+
+  const InstallVerificationInfo({
+    required this.label,
+    required this.body,
+    required this.tone,
+  });
+}
+
+/// Maps the wire value to its localized presentation. Returns null
+/// for an empty/unknown value (pre-0.23 hub) — callers keep their
+/// generic wording then instead of guessing.
+InstallVerificationInfo? describeInstallVerification(
+  String wire,
+  AppLocalizations l,
+) {
+  switch (wire) {
+    case 'pinned-key':
+      return InstallVerificationInfo(
+        label: l.verifPinnedKey,
+        body: l.verifPinnedKeyBody,
+        tone: VerificationTone.good,
+      );
+    case 'trusted-publishers':
+      return InstallVerificationInfo(
+        label: l.verifTrustedPublishers,
+        body: l.verifTrustedPublishersBody,
+        tone: VerificationTone.good,
+      );
+    case 'unverified':
+      return InstallVerificationInfo(
+        label: l.verifUnverified,
+        body: l.verifUnverifiedBody,
+        tone: VerificationTone.warning,
+      );
+    case 'blocked':
+      return InstallVerificationInfo(
+        label: l.verifBlocked,
+        body: l.verifBlockedBody,
+        tone: VerificationTone.danger,
+      );
+    case 'federated':
+      return InstallVerificationInfo(
+        label: l.verifFederated,
+        body: l.verifFederatedBody,
+        tone: VerificationTone.neutral,
+      );
+    default:
+      return null;
+  }
+}