dynamic storage monitoring for custom model directories (#781)

* update storage monitoring to respect custom model directory

* reverted .pbxproj

---------

Co-authored-by: tpae <terencepae@gmail.com>

Author: RaajeevChandran

Packages/OsaurusCore/Services/DirectoryPickerService.swift

@@ -86,6 +86,7 @@ final class DirectoryPickerService: ObservableObject {
 
     private init() {
         loadSavedDirectory()
+        SystemMonitorService.shared.updateStoragePath(Self.effectiveModelsDirectory().path)
     }
 
     /// Load previously saved directory from security-scoped bookmark
@@ -273,6 +274,7 @@ final class DirectoryPickerService: ObservableObject {
     /// Notify the rest of the app that the models directory changed so local models are rescanned.
     private func notifyModelsDirectoryChanged() {
         ModelManager.invalidateLocalModelsCache()
+        SystemMonitorService.shared.updateStoragePath(Self.effectiveModelsDirectory().path)
         NotificationCenter.default.post(name: .localModelsChanged, object: nil)
     }
 

Packages/OsaurusCore/Services/SystemMonitorService.swift

@@ -25,6 +25,7 @@ class SystemMonitorService: ObservableObject {
     @Published var availableStorageGB: Double = 0.0
     @Published var totalStorageGB: Double = 0.0
 
+    private var storagePath: String = NSHomeDirectory()
     private var timer: Timer?
     private var previousCPUInfo: host_cpu_load_info?
 
@@ -66,6 +67,12 @@ class SystemMonitorService: ObservableObject {
         totalStorageGB = storageInfo.totalGB
     }
 
+    /// Update the path used for storage monitoring (when user selects a custom models directory)
+    func updateStoragePath(_ path: String) {
+        storagePath = path
+        updateResourceUsage()
+    }
+
     private func getCPUUsage() -> Double {
         var _ = mach_msg_type_number_t()
         var cpuInfo: host_cpu_load_info = host_cpu_load_info()
@@ -179,7 +186,7 @@ class SystemMonitorService: ObservableObject {
     private func getStorageUsage() -> (availableGB: Double, totalGB: Double) {
         let gb = 1024.0 * 1024.0 * 1024.0
         do {
-            let attrs = try FileManager.default.attributesOfFileSystem(forPath: NSHomeDirectory())
+            let attrs = try FileManager.default.attributesOfFileSystem(forPath: storagePath)
             let total = (attrs[.systemSize] as? NSNumber)?.doubleValue ?? 0
             let free = (attrs[.systemFreeSize] as? NSNumber)?.doubleValue ?? 0
             return (free / gb, total / gb)

Packages/OsaurusCore/Views/Model/ModelDownloadView.swift

@@ -707,7 +707,7 @@ private struct SystemStatusBar: View {
 
             ResourceGauge(
                 label: "Storage",
-                icon: "internaldrive",
+                icon: DirectoryPickerService.shared.hasValidDirectory ? "externaldrive" : "internaldrive",
                 usedFraction: totalStorageGB > 0
                     ? (totalStorageGB - availableStorageGB) / totalStorageGB : 0,
                 detail: String(