refactor: group applyMountedChange callbacks under a single field

Code review on pr-735 flagged `applyMountedChange` for exceeding the
8-parameter limit. The three effect callbacks (`onSetDefaultWorkspace`,
`onSwitchVault`, `onUpdateWorkspaceIdentity`) are now grouped under a
single `callbacks` field. The function's destructure surface drops
from 8 to 6 fields, and the semantic split between "state + change"
and "effects" is now explicit in the type.

No behaviour change; the six existing tests pass unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/status-bar/VaultMenu.applyMountedChange.test.ts

@@ -23,10 +23,8 @@ function callApply(overrides: ChangeOverrides) {
     vaultPath: overrides.vaultPath ?? '/a',
     includedVaults: overrides.includedVaults ?? [vault('/a'), vault('/b')],
     mounted: overrides.mounted ?? false,
-    onSetDefaultWorkspace,
-    onSwitchVault,
-    onUpdateWorkspaceIdentity,
     path: overrides.path ?? '/a',
+    callbacks: { onSetDefaultWorkspace, onSwitchVault, onUpdateWorkspaceIdentity },
   })
   return { onSetDefaultWorkspace, onSwitchVault, onUpdateWorkspaceIdentity }
 }

src/components/status-bar/VaultMenu.tsx

@@ -356,13 +356,15 @@ function useVaultMenuInteractions({
   const handleMountedChange = useCallback((path: string, mounted: boolean) => {
     applyMountedChange({
       defaultPath,
+      vaultPath,
       includedVaults,
       mounted,
-      onSetDefaultWorkspace,
-      onSwitchVault,
-      onUpdateWorkspaceIdentity,
       path,
-      vaultPath,
+      callbacks: {
+        onSetDefaultWorkspace,
+        onSwitchVault,
+        onUpdateWorkspaceIdentity,
+      },
     })
   }, [defaultPath, includedVaults, onSetDefaultWorkspace, onSwitchVault, onUpdateWorkspaceIdentity, vaultPath])
 

src/components/status-bar/vaultMenuMountedChange.ts

@@ -1,14 +1,18 @@
 import type { VaultOption } from './types'
 
-export interface VaultMountChangeRequest {
-  defaultPath: string
-  includedVaults: VaultOption[]
-  mounted: boolean
+export interface VaultMountChangeCallbacks {
   onSetDefaultWorkspace?: (path: string) => void
   onSwitchVault: (path: string) => void
   onUpdateWorkspaceIdentity?: (path: string, patch: Partial<VaultOption>) => void
-  path: string
+}
+
+export interface VaultMountChangeRequest {
+  defaultPath: string
   vaultPath: string
+  includedVaults: VaultOption[]
+  mounted: boolean
+  path: string
+  callbacks: VaultMountChangeCallbacks
 }
 
 function nextIncludedVaultPath(includedVaults: VaultOption[], currentPath: string): string | null {
@@ -17,19 +21,17 @@ function nextIncludedVaultPath(includedVaults: VaultOption[], currentPath: strin
 
 export function applyMountedChange({
   defaultPath,
+  vaultPath,
   includedVaults,
   mounted,
-  onSetDefaultWorkspace,
-  onSwitchVault,
-  onUpdateWorkspaceIdentity,
   path,
-  vaultPath,
+  callbacks,
 }: VaultMountChangeRequest): void {
   if (!mounted && (path === defaultPath || path === vaultPath)) {
     const nextPath = nextIncludedVaultPath(includedVaults, path)
     if (!nextPath) return
-    if (path === defaultPath) onSetDefaultWorkspace?.(nextPath)
-    if (path === vaultPath) onSwitchVault(nextPath)
+    if (path === defaultPath) callbacks.onSetDefaultWorkspace?.(nextPath)
+    if (path === vaultPath) callbacks.onSwitchVault(nextPath)
   }
-  onUpdateWorkspaceIdentity?.(path, { mounted })
+  callbacks.onUpdateWorkspaceIdentity?.(path, { mounted })
 }