fix: remove unused imports/variables caught by vue-tsc

- Remove unused app import in Sidebar.vue
- Remove unused toggleMode function in ThemeToggle.vue
- Remove unused theme variable in SetupWizard.vue
- Remove unused watch import in stores/theme.ts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/layout/Sidebar.vue

@@ -2,15 +2,12 @@
 import { ref, onMounted } from 'vue'
 import { useRouter, useRoute } from 'vue-router'
 import { gql } from '@/lib/gql'
-import { useAppStore } from '@/stores/app'
-
 const emit = defineEmits<{ close: [] }>()
 
 interface DocMeta { slug: string; title: string }
 
 const docs = ref<DocMeta[]>([])
 const loading = ref(true)
-const app = useAppStore()
 const router = useRouter()
 const route = useRoute()
 

frontend/src/components/layout/ThemeToggle.vue

@@ -6,10 +6,6 @@ const theme = useThemeStore()
 const open = ref(false)
 const customHex = ref(theme.customAccent || '#6366f1')
 
-function toggleMode() {
-  theme.setMode(theme.mode === 'dark' ? 'light' : 'dark')
-}
-
 const accentColors: Record<string, string> = {
   blue: '#3b82f6', violet: '#8b5cf6', rose: '#f43f5e',
   emerald: '#10b981', amber: '#f59e0b', cyan: '#06b6d4',

frontend/src/components/wizard/SetupWizard.vue

@@ -8,7 +8,7 @@ import ThemeToggle from '@/components/layout/ThemeToggle.vue'
 
 const router = useRouter()
 const app = useAppStore()
-const theme = useThemeStore()
+useThemeStore() // ensures theme is initialized before ThemeToggle renders
 
 const step = ref(1)
 const totalSteps = 3

frontend/src/stores/theme.ts

@@ -1,5 +1,5 @@
 import { defineStore } from 'pinia'
-import { ref, watch } from 'vue'
+import { ref } from 'vue'
 
 export type ThemeMode = 'dark' | 'light'