fix: replace editor PenTool icon with image-edit icon

Custom SVG showing a landscape image frame with a pencil overlay,
clearly communicating "edit image" instead of the vector pen tool
which read more as Illustrator than Photoshop.

apps/web/src/components/layout/app-layout.tsx

@@ -1,18 +1,11 @@
-import {
-  FolderOpen,
-  LayoutGrid,
-  Menu,
-  PenTool,
-  Settings as SettingsIcon,
-  Workflow,
-  X,
-} from "lucide-react";
+import { FolderOpen, LayoutGrid, Menu, Settings as SettingsIcon, Workflow, X } from "lucide-react";
 import { useState } from "react";
 import { Link } from "react-router-dom";
 import { useMobile } from "@/hooks/use-mobile";
 import { cn } from "@/lib/utils";
 import { useConnectionStore } from "@/stores/connection-store";
 import { Dropzone } from "../common/dropzone";
+import { ImageEditIcon } from "../common/image-edit-icon";
 import { OtterLogo } from "../common/otter-logo";
 import { HelpDialog } from "../help/help-dialog";
 import { SettingsDialog } from "../settings/settings-dialog";
@@ -136,7 +129,7 @@ export function AppLayout({ children, showToolPanel = true, onFiles }: AppLayout
         <nav className="fixed bottom-0 left-0 right-0 z-30 bg-background/95 backdrop-blur-sm border-t border-border flex items-center justify-around px-2 py-1.5">
           <MobileNavItem icon={LayoutGrid} label="Tools" href="/" />
           <MobileNavItem icon={Workflow} label="Automate" href="/automate" />
-          <MobileNavItem icon={PenTool} label="Editor" href="/editor" />
+          <MobileNavItem icon={ImageEditIcon} label="Editor" href="/editor" />
           <MobileNavItem icon={FolderOpen} label="Files" href="/files" />
           <button
             type="button"