open markdown files in the reader, not the editor

The files panel and the Claude Config tab called ipc.request('editor.open')
for every file, which targets the editor — so a .md click never reached the
right-side markdown reader (it opens only when something publishes
('builtin.markdown','selection')). Route .md clicks from the files panel
(tree + filtered rows), the Config tab's file-backed rows, and .md wiki links
in the viewer to that channel; non-.md files still open in the editor. Also
remove the dead DaemonEvent fallback that listened for 'editor.buffer_activated'
(the registry emits 'editor.active-changed').

T-187.

Co-Authored-By: Claude <noreply@anthropic.com>

lib/builtin/claude/src/claude_meta_sidebar.dart

@@ -535,7 +535,8 @@ class _ClaudeMetaSidebarState extends State<ClaudeMetaSidebar> {
   }
 
   /// A tappable row for file-backed items (skills, agents, commands).
-  /// Fires `editor.open` with the path when tapped (D-6, T-183).
+  /// All config items are .md files — opens in the markdown reader panel
+  /// via the kernel MessageBus (D-6, T-183).
   Widget _configFileRow(SurfaceTokens tokens, String name, String? path) {
     final row = Padding(
       padding: const EdgeInsets.only(left: 16, top: 2, bottom: 2),
@@ -546,14 +547,15 @@ class _ClaudeMetaSidebarState extends State<ClaudeMetaSidebar> {
       ),
     );
     if (path == null) return row;
+    void openMarkdown() => ClideKernel.of(context).messages.publish('builtin.markdown', 'selection', {'path': path});
     return Semantics(
       button: true,
       label: name,
       excludeSemantics: true,
-      onTap: () => unawaited(ClideKernel.of(context).ipc.request('editor.open', args: {'path': path})),
+      onTap: openMarkdown,
       child: ClideTappable(
         tooltip: path,
-        onTap: () => unawaited(ClideKernel.of(context).ipc.request('editor.open', args: {'path': path})),
+        onTap: openMarkdown,
         builder: (ctx, hovered, _) => Padding(
           padding: const EdgeInsets.only(left: 16, top: 2, bottom: 2),
           child: ClideText(

lib/builtin/files/src/file_tree_view.dart

@@ -212,14 +212,19 @@ class _FileRow extends StatelessWidget {
 
   void _openFile(BuildContext context, String path) {
     final kernel = ClideKernel.of(context);
-    // editor.open is a daemon-side IPC handler (lib/src/daemon/
-    // editor_commands.dart), not a kernel command. Fire the request
-    // and let the editor extension's controller pick up the
-    // editor.active-changed / editor.opened event — no need to await
-    // or handle the response here.
-    unawaited(
-      kernel.ipc.request('editor.open', args: {'path': path}),
-    );
+    if (path.toLowerCase().endsWith('.md')) {
+      // Route .md files to the markdown reader panel via the kernel MessageBus.
+      kernel.messages.publish('builtin.markdown', 'selection', {'path': path});
+    } else {
+      // editor.open is a daemon-side IPC handler (lib/src/daemon/
+      // editor_commands.dart), not a kernel command. Fire the request
+      // and let the editor extension's controller pick up the
+      // editor.active-changed / editor.opened event — no need to await
+      // or handle the response here.
+      unawaited(
+        kernel.ipc.request('editor.open', args: {'path': path}),
+      );
+    }
   }
 }
 
@@ -282,7 +287,11 @@ class _FilteredFileRow extends StatelessWidget {
     return ClideTappable(
       onTap: () {
         final kernel = ClideKernel.of(context);
-        unawaited(kernel.ipc.request('editor.open', args: {'path': entry.path}));
+        if (entry.path.toLowerCase().endsWith('.md')) {
+          kernel.messages.publish('builtin.markdown', 'selection', {'path': entry.path});
+        } else {
+          unawaited(kernel.ipc.request('editor.open', args: {'path': entry.path}));
+        }
       },
       builder: (context, hovered, _) => Container(
         color: hovered ? tokens.sidebarItemHover : null,

lib/builtin/markdown/src/markdown_viewer.dart

@@ -16,7 +16,6 @@ class _MarkdownViewerState extends State<MarkdownViewer> {
   String? _content;
   String? _error;
   StreamSubscription<Message>? _selectionSub;
-  StreamSubscription<DaemonEvent>? _editorSub;
 
   @override
   void didChangeDependencies() {
@@ -27,20 +26,11 @@ class _MarkdownViewerState extends State<MarkdownViewer> {
       final path = msg.data['path'] as String?;
       if (path != null) _loadFile(path);
     });
-    _editorSub = kernel.events.on<DaemonEvent>().listen((e) {
-      if (e.kind == 'editor.buffer_activated') {
-        final path = e.data['path'] as String?;
-        if (path != null && path.endsWith('.md')) {
-          _loadFile(path);
-        }
-      }
-    });
   }
 
   @override
   void dispose() {
     _selectionSub?.cancel();
-    _editorSub?.cancel();
     super.dispose();
   }
 
@@ -62,7 +52,10 @@ class _MarkdownViewerState extends State<MarkdownViewer> {
 
   void _navigateToRecord(BuildContext context, String id) {
     final kernel = ClideKernel.of(context);
-    if (id.startsWith('T-')) {
+    if (id.toLowerCase().endsWith('.md')) {
+      // Wiki-link to another .md file — open it in the reader.
+      kernel.messages.publish('builtin.markdown', 'selection', {'path': id});
+    } else if (id.startsWith('T-')) {
       kernel.messages.publish('builtin.tickets', 'selection', {'id': id});
     } else {
       kernel.messages.publish('builtin.decisions', 'selection', {'id': id});