feat: add FeatureInstallPrompt component for uninstalled AI tool pages

Show an install prompt instead of the normal tool UI when an AI feature
bundle is not installed. Admins see a one-click install button with SSE
progress tracking and polling fallback; non-admins see a message to
contact their administrator.

apps/web/src/pages/tool-page.tsx

@@ -1,4 +1,4 @@
-import { TOOLS } from "@ashim/shared";
+import { PYTHON_SIDECAR_TOOLS, TOOLS } from "@ashim/shared";
 import {
   CheckCircle2,
   ChevronLeft,
@@ -16,15 +16,18 @@ import { type BgPreviewState, ImageViewer } from "@/components/common/image-view
 import { ReviewPanel } from "@/components/common/review-panel";
 import { SideBySideComparison } from "@/components/common/side-by-side-comparison";
 import { ThumbnailStrip } from "@/components/common/thumbnail-strip";
+import { FeatureInstallPrompt } from "@/components/features/feature-install-prompt";
 import { AppLayout } from "@/components/layout/app-layout";
 import { CropCanvas } from "@/components/tools/crop-canvas";
 import type { EraserCanvasRef } from "@/components/tools/eraser-canvas";
 import { EraserCanvas } from "@/components/tools/eraser-canvas";
 import type { PreviewTransform } from "@/components/tools/rotate-settings";
+import { useAuth } from "@/hooks/use-auth";
 import { useMobile } from "@/hooks/use-mobile";
 import { formatFileSize } from "@/lib/download";
 import { ICON_MAP } from "@/lib/icon-map";
 import { getToolRegistryEntry } from "@/lib/tool-registry";
+import { useFeaturesStore } from "@/stores/features-store";
 import { useFileStore } from "@/stores/file-store";
 
 /** Formats that browsers can render in <img> tags. */
@@ -106,6 +109,13 @@ export function ToolPage() {
     () => (toolId ? getToolRegistryEntry(toolId) : undefined),
     [toolId],
   );
+  const isAiTool = toolId ? (PYTHON_SIDECAR_TOOLS as readonly string[]).includes(toolId) : false;
+  const getBundleForTool = useFeaturesStore((s) => s.getBundleForTool);
+  const isToolInstalled = useFeaturesStore((s) => s.isToolInstalled);
+  const featureBundle = toolId ? getBundleForTool(toolId) : null;
+  const toolInstalled = toolId ? isToolInstalled(toolId) : true;
+  const { hasPermission } = useAuth();
+  const isAdmin = hasPermission("settings:write");
   const {
     files,
     entries,
@@ -234,6 +244,14 @@ export function ToolPage() {
     );
   }
 
+  if (isAiTool && !toolInstalled && featureBundle) {
+    return (
+      <AppLayout>
+        <FeatureInstallPrompt bundle={featureBundle} isAdmin={isAdmin} />
+      </AppLayout>
+    );
+  }
+
   const IconComponent =
     (ICON_MAP[tool.icon] as React.ComponentType<{ className?: string }>) ?? FileImage;