fix: resolve iOS freezes and expand offline library

TiebaPure.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		B1C2D3E4F5061728394A5B6C /* SavedThreadMedia.swift in Sources */ = {isa = PBXBuildFile; fileRef = A1B2C3D4E5F60718293A4B5C /* SavedThreadMedia.swift */; };
 		03BFC1CB27519F2A9851619C /* ContentDraft.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5A1C1C285AED2131947564A /* ContentDraft.swift */; };
 		043AF9BB1E2EF30D61B1DC63 /* SwiftDataOrderedCollectionPersistence.swift in Sources */ = {isa = PBXBuildFile; fileRef = 67285F50B29BA765B74B5271 /* SwiftDataOrderedCollectionPersistence.swift */; };
 		06132F36C724DF5F6A7409D5 /* ThreadDetailView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1626D4B0DD88E88576EBC2EB /* ThreadDetailView.swift */; };
@@ -258,6 +259,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		A1B2C3D4E5F60718293A4B5C /* SavedThreadMedia.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SavedThreadMedia.swift; sourceTree = "<group>"; };
 		00339148CB9511CB5F6A624F /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist; path = Info.plist; sourceTree = "<group>"; };
 		0060EA54C03E209E46FB2C40 /* ForumThreadsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ForumThreadsView.swift; sourceTree = "<group>"; };
 		00A0FAAA54B2D05276E46330 /* SessionExpirationMonitorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SessionExpirationMonitorTests.swift; sourceTree = "<group>"; };
@@ -637,6 +639,7 @@
 				638DEF254549D0D4DE625487 /* ReadingPreferences.swift */,
 				FDE02417BF13C2E0A1D7824E /* RecentForum.swift */,
 				0DB03A9A81B77E7ECBD00B30 /* SavedThread.swift */,
+				A1B2C3D4E5F60718293A4B5C /* SavedThreadMedia.swift */,
 				24D4BAC59CD64A3B8F236258 /* SearchHistory.swift */,
 				16DDB351392A69BC42810B9E /* SearchResult.swift */,
 				6BBA032F531024778CFC5C0A /* SecureFilePersistence.swift */,
@@ -1219,6 +1222,7 @@
 				A4FCD6601BAA005BF0F264D0 /* RootView.swift in Sources */,
 				C02D20CEC3FEDED464983D96 /* SafariActionPayload.swift in Sources */,
 				1E84B72ACDF13678A6BE6CB8 /* SavedThread.swift in Sources */,
+				B1C2D3E4F5061728394A5B6C /* SavedThreadMedia.swift in Sources */,
 				985218E469AF18B5378E8549 /* SavedThreadsView.swift in Sources */,
 				CAA7C941E2D8AAA65B342CBA /* SearchHistory.swift in Sources */,
 				8028A9708BDE36C7BB815CEF /* SearchResult.swift in Sources */,

TiebaPure/App/RootView.swift

@@ -431,24 +431,18 @@ private struct TabSelectionObserver: UIViewControllerRepresentable {
             visited: inout Set<ObjectIdentifier>
         ) -> UITabBarController? {
             guard let controller else { return nil }
-
-            let identifier = ObjectIdentifier(controller)
-            guard visited.insert(identifier).inserted else { return nil }
-
+            guard visited.insert(ObjectIdentifier(controller)).inserted else { return nil }
             if let tabBarController = controller as? UITabBarController {
                 return tabBarController
             }
-
             if let found = findTabBarController(from: controller.presentedViewController, visited: &visited) {
                 return found
             }
-
             for child in controller.children {
                 if let found = findTabBarController(from: child, visited: &visited) {
                     return found
                 }
             }
-
             return nil
         }
     }
@@ -467,9 +461,7 @@ private struct TabSelectionObserver: UIViewControllerRepresentable {
                 return
             }
             detach()
-            if tabBarController.delegate !== self {
-                previousDelegate = tabBarController.delegate
-            }
+            previousDelegate = tabBarController.delegate
             observedController = tabBarController
             tabBarController.delegate = self
         }
@@ -495,9 +487,7 @@ private struct TabSelectionObserver: UIViewControllerRepresentable {
             if tabBarController.selectedViewController === viewController,
                tabBarController.viewControllers?.first === viewController {
                 let callback = onReselectHome
-                DispatchQueue.main.async {
-                    callback()
-                }
+                DispatchQueue.main.async(execute: callback)
             }
             return true
         }

TiebaPure/App/TiebaPureApp.swift

@@ -6,6 +6,7 @@ struct TiebaPureApp: App {
     @StateObject private var environment = AppEnvironment.live()
     @StateObject private var appearanceStore = AppAppearanceStore.live()
     @StateObject private var readingPreferencesStore = ReadingPreferencesStore.live()
+    @StateObject private var readerFontStore = ReaderFontStore.shared
 
     var body: some Scene {
         WindowGroup {
@@ -30,8 +31,13 @@ struct TiebaPureApp: App {
             .environmentObject(environment.forumSignCoordinator)
             .environmentObject(appearanceStore)
             .environmentObject(readingPreferencesStore)
+            .environmentObject(readerFontStore)
             .environment(\.readingPreferences, readingPreferencesStore.preferences)
             .preferredColorScheme(appearanceStore.selection.preferredColorScheme)
+            .task(id: readerFontStore.isReady) {
+                guard readerFontStore.isReady else { return }
+                readingPreferencesStore.reconcileAvailableImportedFonts(readerFontStore.entries)
+            }
         }
     }
 }

TiebaPure/Core/UI/AvatarView.swift

@@ -47,10 +47,15 @@ enum TiebaImageSourcePolicy {
     static func urls(primary: URL?, fallback: URL? = nil) -> [URL] {
         var result: [URL] = []
         for candidate in [primary, fallback].compactMap({ $0 }) {
-            guard let safeURL = TiebaURL.image(candidate.absoluteString),
-                  result.contains(safeURL) == false else {
+            let safeURL: URL
+            if SavedThreadMediaAuthorization.shared.allows(candidate) {
+                safeURL = candidate
+            } else if let validated = TiebaURL.image(candidate.absoluteString) {
+                safeURL = validated
+            } else {
                 continue
             }
+            guard result.contains(safeURL) == false else { continue }
             result.append(safeURL)
         }
         return result
@@ -271,8 +276,13 @@ actor TiebaImagePipeline {
     ) async throws -> UIImage {
         // Download the validated URL, not the caller's: validation may have
         // upgraded a legacy http source to https.
-        guard let safeURL = TiebaURL.image(url.absoluteString),
-              redirectScope.allows(safeURL) || Self.isSyntheticFixtureURL(safeURL) else {
+        let safeURL: URL
+        if SavedThreadMediaAuthorization.shared.allows(url) {
+            safeURL = url
+        } else if let validated = TiebaURL.image(url.absoluteString),
+                  redirectScope.allows(validated) || Self.isSyntheticFixtureURL(validated) {
+            safeURL = validated
+        } else {
             throw TiebaImagePipelineError.invalidURL
         }
         guard TiebaImageSourcePolicy.isSyntheticFailureURL(url) == false else {
@@ -386,7 +396,7 @@ actor TiebaImagePipeline {
             } catch {
                 result = .failure(error)
             }
-            await self.completeSharedRequest(
+            self.completeSharedRequest(
                 request,
                 operationID: operationID,
                 result: result
@@ -445,6 +455,25 @@ actor TiebaImagePipeline {
         session: URLSession,
         onProgress: (@Sendable (BoundedURLSessionProgress) async -> Void)?
     ) async throws -> UIImage {
+        if request.url.isFileURL {
+            guard SavedThreadMediaAuthorization.shared.allows(request.url) else {
+                throw TiebaImagePipelineError.invalidURL
+            }
+            let data = try Data(contentsOf: request.url, options: [.mappedIfSafe, .uncached])
+            guard data.isEmpty == false,
+                  data.count <= maximumImageBytes,
+                  let image = decodedImage(
+                    from: data,
+                    targetPixelSize: request.targetPixelSize
+                  ) else {
+                throw TiebaImagePipelineError.invalidImageData
+            }
+            await onProgress?(BoundedURLSessionProgress(
+                receivedBytes: data.count,
+                expectedBytes: data.count
+            ))
+            return image
+        }
         var attempt = 0
         while true {
             do {

TiebaPure/Core/UI/InteractiveNavigationPop.swift

@@ -42,7 +42,12 @@ enum NativeEdgePopGestureActivationPolicy {
 
 enum NavigationPopGestureControlHostingPolicy {
     static func requiresController(systemMajorVersion: Int, isEnabled: Bool) -> Bool {
-        isEnabled == false || systemMajorVersion < 26
+        _ = systemMajorVersion
+        // A normal NavigationStack must keep complete ownership of its native
+        // recognizers. Hosting a controller merely to force-enable the edge
+        // recognizer raced SwiftUI's push transition on iOS 16-18, especially
+        // when two navigation stacks were visible in an iPad split view.
+        return isEnabled == false
     }
 }
 
@@ -171,7 +176,7 @@ private struct NativeNavigationPopGestureControl: UIViewControllerRepresentable
         private func applyRequestedState() {
             guard requestedEnabled == false else {
                 restorePopGesturesIfNeeded()
-                enableNativeEdgePopIfNeeded()
+                updateDiagnostics(using: navigationController)
                 return
             }
             guard let navigationController else { return }

TiebaPure/Domain/Models/ContentBlock.swift

@@ -107,8 +107,15 @@ enum ContentBlock: Equatable, Codable, Sendable {
 struct VoiceContent: Equatable, Codable, Sendable {
     let md5: String
     let durationMilliseconds: Int
+    var localURL: URL?
+    var offlineOnly: Bool?
 
-    init?(md5: String, durationMilliseconds: Int) {
+    init?(
+        md5: String,
+        durationMilliseconds: Int,
+        localURL: URL? = nil,
+        offlineOnly: Bool? = nil
+    ) {
         let normalizedMD5 = md5
             .trimmingCharacters(in: .whitespacesAndNewlines)
             .lowercased()
@@ -119,6 +126,8 @@ struct VoiceContent: Equatable, Codable, Sendable {
 
         self.md5 = normalizedMD5
         self.durationMilliseconds = max(durationMilliseconds, 0)
+        self.localURL = localURL
+        self.offlineOnly = offlineOnly
     }
 
     private static func isLowercaseHexDigit(_ byte: UInt8) -> Bool {