web: deep-link openApp/appArgs/autoOpen — pre-select & pre-fill an app from the URL (#1577)

Closes #1577

Extends the deep link (#1576) to land on a rendered MCP App:

- `&openApp=<toolName>` — once connected and the tool appears in the app list,
  InspectorView switches to the Apps tab and pre-selects it.
- `&appArgs=<base64url(JSON)>` — pre-fills the tool form; values are merged
  **over** `collectSchemaDefaults()` so required-with-default fields don't
  disable "Open App".
- `&autoOpen=<token>` — token-gated auto-click of "Open App".

Adapted to the current architecture (differs from PR #1510's reference):
- Tab state is lifted to App.tsx (#1417), so the openApp effect lives in
  InspectorView and drives `onActiveTabChange("Apps")` + `onAppsUiChange` seed
  + `onSelectApp`, guarded by `deepLinkOpenAppRef` to fire once.
- AppsScreen owns the `running`/iframe state, so `autoOpen` is threaded to it
  as a prop; a fire-once effect defers the open one microtask past the
  synchronous effect body (satisfying `react-hooks/set-state-in-effect`,
  matching App.tsx's connect effect). `resetAppChannels` memoized so the
  effect's deps don't churn.

Tests: InspectorView (tab-switch + pre-select + appArgs-over-defaults merge +
non-app openApp ignored), AppsScreen (autoOpen fires once with seeded values;
no-selection stays idle). README documents the params. Coverage gate green.

Part of the #1579 decomposition (Wave 4).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BrihGWcrM9JGRyu41nzZYw

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

@@ -274,6 +274,40 @@ describe("AppsScreen", () => {
     expect(screen.getByTitle("Ops Dashboard")).toBeInTheDocument();
   });
 
+  it("auto-opens the pre-selected app with its seeded form values when autoOpen is set (deep-link)", async () => {
+    const onOpenApp = vi.fn();
+    renderWithMantine(
+      <ControlledAppsScreen
+        autoOpen
+        ui={{
+          selectedAppName: "weather",
+          formValues: { city: "Reykjavik" },
+          search: "",
+        }}
+        onOpenApp={onOpenApp}
+      />,
+    );
+    // No click: the fire-once effect opens the seeded app with its form values.
+    await vi.waitFor(() =>
+      expect(onOpenApp).toHaveBeenCalledWith("weather", { city: "Reykjavik" }),
+    );
+    expect(onOpenApp).toHaveBeenCalledTimes(1);
+    // Renderer mounted; the Open App button is gone.
+    expect(
+      screen.queryByRole("button", { name: /Open App/ }),
+    ).not.toBeInTheDocument();
+    expect(screen.getByTitle("Weather Widget")).toBeInTheDocument();
+  });
+
+  it("does not auto-open when autoOpen is set but no app is pre-selected", async () => {
+    const onOpenApp = vi.fn();
+    renderWithMantine(<ControlledAppsScreen autoOpen onOpenApp={onOpenApp} />);
+    // Give the effect a chance to run; with no selection it must stay idle.
+    await Promise.resolve();
+    expect(onOpenApp).not.toHaveBeenCalled();
+    expect(screen.getByText("Select an app to view details")).toBeVisible();
+  });
+
   it("invokes onOpenApp with form values when Open App is clicked", async () => {
     const user = userEvent.setup();
     const onOpenApp = vi.fn();