feat: add "+ App" shortcut button to sidebar Applications header

Adds a subtle "+ App" button in the sidebar section header for quick
app creation without navigating to the Deployments tab first. Only
visible to OPERATOR and ADMIN roles.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/components/LayoutShell.module.css

@@ -43,6 +43,34 @@
   opacity: 0.6;
 }
 
+.appSectionWrap {
+  position: relative;
+}
+
+.addAppBtn {
+  position: absolute;
+  top: 6px;
+  right: 6px;
+  z-index: 1;
+  display: flex;
+  align-items: center;
+  gap: 2px;
+  background: none;
+  border: none;
+  padding: 2px 6px;
+  border-radius: 4px;
+  font-size: 12px;
+  font-weight: 500;
+  color: var(--sidebar-muted);
+  cursor: pointer;
+  transition: color 0.12s, background 0.12s;
+}
+
+.addAppBtn:hover {
+  color: var(--amber);
+  background: rgba(255, 255, 255, 0.06);
+}
+
 .mainContent {
   flex: 1;
   display: flex;

ui/src/components/LayoutShell.tsx

@@ -21,7 +21,7 @@ import {
 } from '@cameleer/design-system';
 import type { SearchResult, SidebarTreeNode, DropdownItem, ButtonGroupItem, ExchangeStatus } from '@cameleer/design-system';
 import sidebarLogo from '@cameleer/design-system/assets/cameleer3-logo.svg';
-import { Box, Settings, FileText, ChevronRight, Square, Pause, Star, X, User } from 'lucide-react';
+import { Box, Settings, FileText, ChevronRight, Square, Pause, Star, X, User, Plus } from 'lucide-react';
 import { AboutMeDialog } from './AboutMeDialog';
 import css from './LayoutShell.module.css';
 import { useQueryClient } from '@tanstack/react-query';
@@ -31,7 +31,7 @@ import { useSearchExecutions, useAttributeKeys } from '../api/queries/executions
 import { useUsers, useGroups, useRoles } from '../api/queries/admin/rbac';
 import { useEnvironments } from '../api/queries/admin/environments';
 import type { UserDetail, GroupDetail, RoleDetail } from '../api/queries/admin/rbac';
-import { useAuthStore, useIsAdmin } from '../auth/auth-store';
+import { useAuthStore, useIsAdmin, useCanControl } from '../auth/auth-store';
 import { useEnvironmentStore } from '../api/environment-store';
 import { useState, useMemo, useCallback, useEffect, useRef, createElement } from 'react';
 import type { ReactNode } from 'react';
@@ -296,6 +296,7 @@ function LayoutContent() {
 
   // --- Role checks ----------------------------------------------------
   const isAdmin = useIsAdmin();
+  const canControl = useCanControl();
 
   // --- Environment filtering -----------------------------------------
   const selectedEnv = useEnvironmentStore((s) => s.environment);
@@ -692,23 +693,34 @@ function LayoutContent() {
       />
 
       {/* Applications section */}
-      <Sidebar.Section
-        icon={createElement(Box, { size: 16 })}
-        label="Applications"
-        open={appsOpen}
-        onToggle={toggleApps}
-      >
-        <SidebarTree
-          nodes={appTreeNodes}
-          selectedPath={effectiveSelectedPath}
-          isStarred={isStarred}
-          onToggleStar={toggleStar}
-          filterQuery={filterQuery}
-          persistKey="apps"
-          autoRevealPath={sidebarRevealPath}
-          onNavigate={handleSidebarNavigate}
-        />
-      </Sidebar.Section>
+      <div className={css.appSectionWrap}>
+        {canControl && (
+          <button
+            className={css.addAppBtn}
+            onClick={(e) => { e.stopPropagation(); navigate('/apps/new'); }}
+            title="Create App"
+          >
+            <Plus size={12} /> App
+          </button>
+        )}
+        <Sidebar.Section
+          icon={createElement(Box, { size: 16 })}
+          label="Applications"
+          open={appsOpen}
+          onToggle={toggleApps}
+        >
+          <SidebarTree
+            nodes={appTreeNodes}
+            selectedPath={effectiveSelectedPath}
+            isStarred={isStarred}
+            onToggleStar={toggleStar}
+            filterQuery={filterQuery}
+            persistKey="apps"
+            autoRevealPath={sidebarRevealPath}
+            onNavigate={handleSidebarNavigate}
+          />
+        </Sidebar.Section>
+      </div>
 
       {/* Starred section — only when there are starred items */}
       {starredItems.length > 0 && (