Auto-read resource on sidebar click

Clicking a resource in the URIs accordion now triggers onReadResource
in addition to setting the selection, so the preview panel jumps
straight to the pending → ok render path. Removes the unreachable
"Click to read this resource" placeholder, since the loader / preview /
error states always cover the rendered output for a selected resource.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: cliffhall

clients/web/src/components/screens/ResourcesScreen/ResourcesScreen.test.tsx

@@ -114,11 +114,14 @@ describe("ResourcesScreen", () => {
     ).toBeInTheDocument();
   });
 
-  it("renders empty state when a resource is selected but no readState", async () => {
+  it("auto-reads when a resource is clicked in the sidebar", async () => {
     const user = userEvent.setup();
-    renderWithMantine(<ResourcesScreen {...baseProps} />);
+    const onReadResource = vi.fn();
+    renderWithMantine(
+      <ResourcesScreen {...baseProps} onReadResource={onReadResource} />,
+    );
     await user.click(screen.getByText("x.txt"));
-    expect(screen.getByText("Click to read this resource")).toBeInTheDocument();
+    expect(onReadResource).toHaveBeenCalledWith("file:///x");
   });
 
   it("forwards refresh and subscribe events from the preview panel", async () => {

clients/web/src/components/screens/ResourcesScreen/ResourcesScreen.tsx

@@ -107,6 +107,7 @@ export function ResourcesScreen({
   function handleSelectResource(uri: string) {
     setSelectedTemplateUri(undefined);
     setSelectedResourceUri(uri);
+    onReadResource(uri);
   }
 
   function handleSelectTemplate(uriTemplate: string) {
@@ -201,11 +202,7 @@ export function ResourcesScreen({
         </Group>
       ) : selectedResource ? (
         <ScrollArea.Autosize flex={1} mah={SCROLL_MAX_HEIGHT}>
-          {renderReadState() ?? (
-            <DetailCard>
-              <EmptyState>Click to read this resource</EmptyState>
-            </DetailCard>
-          )}
+          {renderReadState()}
         </ScrollArea.Autosize>
       ) : (
         <DetailCard flex={1}>