feat(studio): operator-mode pass — Store + audit detail + channel switcher (v0.10.0)

Turns Studio from read-only dashboard into operator console.
Pieces:

  * **New Store page** (sidebar destination #3): browses the
    hub's bundled store-index with query + category + status
    filters. Each card has an Install button that prompts for
    the `.fai` bundle source (URL or local path), ships it to
    HubAdmin.InstallModule, shows success / error in a progress
    dialog, refreshes the list.

  * **Audit drill-down**: every event row is now tappable;
    opens a modal with all LoggedEvent fields including the
    new `detail` JSON pretty-printed in a code block. KRITIS
    forensic story: every audit row → full structured detail
    in two clicks.

  * **Approvals payload preview**: shipped already; now
    pretty-prints JSON when the preview parses as such, plus
    a clearer `PAYLOAD PREVIEW` label. Reviewer identity
    defaults to `$USER@studio` instead of the hard-coded
    `studio-mvp` so the audit trail records who acted.

  * **Channel switcher in Settings dialog**: the dialog now
    pulls HubAdmin.ChannelStatus and renders one row per
    channel (local / dev / beta / production) with port,
    running indicator, active marker. A "Connect" button
    on a running channel sets Studio's endpoint to that
    channel's port and reconnects in one click.

Cmd+1..6 keyboard shortcuts updated for the six destinations.
Widget test asserts every destination renders.

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

lib/data/hub.dart

@@ -106,6 +106,74 @@ class HubService {
     );
   }
 
+  /// Active channel + per-channel daemon status snapshot.
+  Future<ChannelStatusSnapshot> channelStatus() async {
+    final r = await _client.channelStatus();
+    return ChannelStatusSnapshot(
+      active: r.active,
+      channels: r.channels
+          .map(
+            (c) => ChannelInfo(
+              name: c.name,
+              port: c.port,
+              running: c.running,
+              endpoint: c.endpoint,
+            ),
+          )
+          .toList(),
+    );
+  }
+
+  /// Browse the bundled store index. All filters optional;
+  /// empty query returns the first [limit] entries.
+  Future<List<StoreItem>> searchStore({
+    String query = '',
+    String category = '',
+    String tag = '',
+    String status = '',
+    int limit = 50,
+  }) async {
+    final entries = await _client.searchStore(
+      query: query,
+      category: category,
+      tag: tag,
+      status: status,
+      limit: limit,
+    );
+    return entries
+        .map(
+          (e) => StoreItem(
+            name: e.name,
+            taglineEn: e.taglineEn,
+            descriptionEn: e.descriptionEn,
+            category: e.category,
+            tags: e.tags,
+            requiresCapabilities: e.requiresCapabilities,
+            requiresServices: e.requiresServices,
+            license: e.license,
+            repository: e.repository,
+            bestVersion: e.bestVersion,
+            status: e.status,
+            installed: e.installed,
+          ),
+        )
+        .toList();
+  }
+
+  /// Install a module from a `.fai` bundle (URL or local path).
+  /// Returns the installed module's name + version on success;
+  /// throws on hub error (signature mismatch, sha256 fail, etc.).
+  Future<({String name, String version})> installModule({
+    required String source,
+    String expectedSha256 = '',
+  }) async {
+    final r = await _client.installModule(
+      source: source,
+      expectedSha256: expectedSha256,
+    );
+    return (name: r.name, version: r.version);
+  }
+
   /// Saved flows known to the hub.
   Future<List<SavedFlow>> listFlows() async {
     final flows = await _client.listFlows();
@@ -163,8 +231,15 @@ class HubService {
             flowName: e.flowName.isEmpty ? null : e.flowName,
             stepId: e.stepId.isEmpty ? null : e.stepId,
             moduleName: e.moduleName.isEmpty ? null : e.moduleName,
+            moduleVersion:
+                e.moduleVersion.isEmpty ? null : e.moduleVersion,
+            invocationId:
+                e.invocationId.isEmpty ? null : e.invocationId,
+            flowExecution:
+                e.flowExecution.isEmpty ? null : e.flowExecution,
             durationMs: e.durationMs == 0 ? null : e.durationMs.toInt(),
             error: e.error.isEmpty ? null : e.error,
+            detail: e.detail.isEmpty ? null : e.detail,
           ),
         )
         .toList();
@@ -378,8 +453,14 @@ class AuditEvent {
   final String? flowName;
   final String? stepId;
   final String? moduleName;
+  final String? moduleVersion;
+  final String? invocationId;
+  final String? flowExecution;
   final int? durationMs;
   final String? error;
+  /// Free-form JSON-string carrying event-type-specific fields.
+  /// Surfaced verbatim in the audit drill-down dialog.
+  final String? detail;
 
   const AuditEvent({
     required this.eventId,
@@ -388,8 +469,12 @@ class AuditEvent {
     this.flowName,
     this.stepId,
     this.moduleName,
+    this.moduleVersion,
+    this.invocationId,
+    this.flowExecution,
     this.durationMs,
     this.error,
+    this.detail,
   });
 }
 
@@ -412,3 +497,59 @@ class PendingApproval {
     this.expiresAt,
   });
 }
+
+class ChannelInfo {
+  final String name;
+  final int port;
+  final bool running;
+  final String endpoint;
+
+  const ChannelInfo({
+    required this.name,
+    required this.port,
+    required this.running,
+    required this.endpoint,
+  });
+}
+
+class ChannelStatusSnapshot {
+  final String active;
+  final List<ChannelInfo> channels;
+
+  const ChannelStatusSnapshot({
+    required this.active,
+    required this.channels,
+  });
+}
+
+/// One row from the store-index search.
+class StoreItem {
+  final String name;
+  final String taglineEn;
+  final String descriptionEn;
+  final String category;
+  final List<String> tags;
+  final List<String> requiresCapabilities;
+  final List<String> requiresServices;
+  final String license;
+  final String repository;
+  final String bestVersion;
+  /// "published", "alpha", "planned", or empty when unknown.
+  final String status;
+  final bool installed;
+
+  const StoreItem({
+    required this.name,
+    required this.taglineEn,
+    required this.descriptionEn,
+    required this.category,
+    required this.tags,
+    required this.requiresCapabilities,
+    required this.requiresServices,
+    required this.license,
+    required this.repository,
+    required this.bestVersion,
+    required this.status,
+    required this.installed,
+  });
+}