fix(jordanbaird#530): Remove expired CGImages from cache

Adapted from upstream PR jordanbaird#804 by Marc A. Runkel for the macos-26
baseline: the original referenced `MenuBarItemManager.ItemCache.allItems`
(removed on macos-26 when ItemCache was simplified — the all/managed
distinction was dropped). Replaced with `ItemCache.managedItems`. The
cache-key type also changed: macos-26 keys MenuBarItemImageCache.images
by `MenuBarItemTag`, not `MenuBarItemInfo`. Filter-then-merge order
preserved from the original; behavioural intent is identical — sweep
the image cache and drop entries whose key no longer matches any
currently-managed menu bar item, addressing the memory growth reported
in upstream issue jordanbaird#530.

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

Author: mrunkel

Ice/MenuBar/MenuBarItems/MenuBarItemImageCache.swift

@@ -264,7 +264,13 @@ final class MenuBarItemImageCache: ObservableObject {
             newImages.merge(sectionImages) { (_, new) in new }
         }
 
-        await MainActor.run { [newImages] in
+        // Adapted from upstream PR #804 by Marc A. Runkel (#530) — original used ItemCache.allItems; replaced with the macos-26 enumeration.
+        let allValidTags = await Set(appState.itemManager.itemCache.managedItems.map(\.tag))
+
+        await MainActor.run { [newImages, allValidTags] in
+            // Drop entries whose key no longer matches any currently-cached menu bar item.
+            images = images.filter { allValidTags.contains($0.key) }
+            // Merge in the freshly captured images.
             images.merge(newImages) { (_, new) in new }
         }
     }