[refactor] Consolidate settings migration logic into dedicated utility

- Extract all migrateDeprecatedValue logic from individual settings into centralized settingsMigration.ts
- Remove migrateDeprecatedValue from SettingParams interface and coreSettings definitions
- Simplify settingStore by removing tryMigrateDeprecatedValue function
- Ensure migrations run after loadSettingValues() for clean initialization flow
- Update tests to reflect new migration approach

This refactor centralizes all setting value migrations in one place, making them easier to maintain and avoiding timing issues with settings that don't exist yet.

src/utils/migration/settingsMigration.ts

@@ -0,0 +1,83 @@
+import type { Keybinding } from '@/schemas/keyBindingSchema'
+import { useSettingStore } from '@/stores/settingStore'
+
+export interface SettingMigration {
+  condition: () => boolean
+  migrate: () => Promise<void>
+}
+
+/**
+ * Setting value migrations that transform deprecated values to new formats.
+ * These run after settings are loaded from the server but before they are
+ * registered, ensuring settings have valid values when the app initializes.
+ */
+export const SETTING_MIGRATIONS: SettingMigration[] = [
+  // Migrate Comfy.UseNewMenu "Floating" value to "Top"
+  {
+    condition: () => {
+      const settingStore = useSettingStore()
+      return (
+        settingStore.exists('Comfy.UseNewMenu') &&
+        (settingStore.get('Comfy.UseNewMenu') as string) === 'Floating'
+      )
+    },
+    migrate: async () => {
+      const settingStore = useSettingStore()
+      await settingStore.set('Comfy.UseNewMenu', 'Top')
+    }
+  },
+  // Migrate Comfy.Keybinding.UnsetBindings targetSelector to targetElementId
+  {
+    condition: () => {
+      const settingStore = useSettingStore()
+      if (!settingStore.exists('Comfy.Keybinding.UnsetBindings')) return false
+      const keybindings = settingStore.get(
+        'Comfy.Keybinding.UnsetBindings'
+      ) as Keybinding[]
+      return keybindings.some((kb: any) => 'targetSelector' in kb)
+    },
+    migrate: async () => {
+      const settingStore = useSettingStore()
+      const keybindings = settingStore.get(
+        'Comfy.Keybinding.UnsetBindings'
+      ) as any[]
+      const migrated = keybindings.map((keybinding) => {
+        if (keybinding['targetSelector'] === '#graph-canvas') {
+          keybinding['targetElementId'] = 'graph-canvas'
+          delete keybinding['targetSelector']
+        }
+        return keybinding
+      })
+      await settingStore.set('Comfy.Keybinding.UnsetBindings', migrated)
+    }
+  },
+  // Migrate Comfy.ColorPalette custom_ prefix
+  {
+    condition: () => {
+      const settingStore = useSettingStore()
+      return (
+        settingStore.exists('Comfy.ColorPalette') &&
+        (settingStore.get('Comfy.ColorPalette') as string).startsWith('custom_')
+      )
+    },
+    migrate: async () => {
+      const settingStore = useSettingStore()
+      const value = settingStore.get('Comfy.ColorPalette') as string
+      await settingStore.set('Comfy.ColorPalette', value.replace('custom_', ''))
+    }
+  }
+]
+
+/**
+ * Runs all setting migrations that meet their conditions.
+ * This is called after loadSettingValues() to ensure all deprecated
+ * setting values are migrated to their current format before the
+ * application starts using them.
+ */
+export async function runSettingMigrations(): Promise<void> {
+  for (const migration of SETTING_MIGRATIONS) {
+    if (migration.condition()) {
+      await migration.migrate()
+    }
+  }
+}