chore(ios): add Share Extension execution trace diagnostics (temporary)

Add a lightweight, temporary trace logger to diagnose where the iOS
Share Extension stops executing during a failed cold-start share.

- ShareViewController: add appendTrace() helper that writes ISO8601-
  prefixed lines to share-extension-trace.log in the App Group
  container, ignoring failures (diagnostics only)
- Add trace entries across the share flow: viewDidLoad,
  processAndOpenApp, processSharedImage, image attachment/load,
  storeImageData, setSharedPhotoReadyFlag, openMainApp, completeRequest
- SharedImageUtility: add getShareExtensionTrace() (read-only) and
  clearShareExtensionTrace() (deletes the trace file)
- SharedImagePlugin: expose getShareExtensionTrace() and
  clearShareExtensionTrace() to JS
- definitions.ts / SharedImagePlugin.web.ts: add ShareExtensionTrace
  type, method signatures, and web stubs

Share behavior is unchanged and Android is untouched. All additions are
marked with "TEMPORARY SHARE TARGET DIAGNOSTICS".

ios/App/App/SharedImagePlugin.swift

@@ -25,7 +25,11 @@ public class SharedImagePlugin: CAPPlugin, CAPBridgedPlugin {
         return [
             CAPPluginMethod(#selector(getSharedImage(_:)), returnType: .promise),
             CAPPluginMethod(#selector(hasSharedImage(_:)), returnType: .promise),
-            CAPPluginMethod(#selector(getShareExtensionDiagnostics(_:)), returnType: .promise)
+            CAPPluginMethod(#selector(getShareExtensionDiagnostics(_:)), returnType: .promise),
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            CAPPluginMethod(#selector(getShareExtensionTrace(_:)), returnType: .promise),
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            CAPPluginMethod(#selector(clearShareExtensionTrace(_:)), returnType: .promise)
         ]
     }
     
@@ -70,5 +74,24 @@ public class SharedImagePlugin: CAPPlugin, CAPBridgedPlugin {
     @objc public func getShareExtensionDiagnostics(_ call: CAPPluginCall) {
         call.resolve(SharedImageUtility.getShareExtensionDiagnostics())
     }
+
+    // TEMPORARY SHARE TARGET DIAGNOSTICS
+    /**
+     * Return the raw Share Extension execution trace log from the App Group container
+     */
+    @objc public func getShareExtensionTrace(_ call: CAPPluginCall) {
+        call.resolve([
+            "trace": SharedImageUtility.getShareExtensionTrace()
+        ])
+    }
+
+    // TEMPORARY SHARE TARGET DIAGNOSTICS
+    /**
+     * Delete the Share Extension execution trace log if present
+     */
+    @objc public func clearShareExtensionTrace(_ call: CAPPluginCall) {
+        SharedImageUtility.clearShareExtensionTrace()
+        call.resolve()
+    }
 }
 

ios/App/App/SharedImageUtility.swift

@@ -16,6 +16,8 @@ public class SharedImageUtility {
     private static let sharedPhotoShareIdKey = "sharedPhotoShareId"
     private static let shareExtensionLastStartKey = "shareExtensionLastStart"
     private static let sharedPhotoReadyKey = "sharedPhotoReady"
+    // TEMPORARY SHARE TARGET DIAGNOSTICS
+    private static let shareExtensionTraceFileName = "share-extension-trace.log"
     
     /// Get the App Group container URL for accessing shared files
     private static var appGroupContainerURL: URL? {
@@ -145,6 +147,33 @@ public class SharedImageUtility {
         ]
     }
 
+    // TEMPORARY SHARE TARGET DIAGNOSTICS
+    /**
+     * Read the Share Extension trace file from the App Group container.
+     * Read-only: does not modify or delete the trace file.
+     *
+     * @returns the full trace contents, or an empty string if no trace exists
+     */
+    static func getShareExtensionTrace() -> String {
+        guard let containerURL = appGroupContainerURL else {
+            return ""
+        }
+        let fileURL = containerURL.appendingPathComponent(shareExtensionTraceFileName)
+        return (try? String(contentsOf: fileURL, encoding: .utf8)) ?? ""
+    }
+
+    // TEMPORARY SHARE TARGET DIAGNOSTICS
+    /**
+     * Delete the Share Extension trace file from the App Group container if present.
+     */
+    static func clearShareExtensionTrace() {
+        guard let containerURL = appGroupContainerURL else {
+            return
+        }
+        let fileURL = containerURL.appendingPathComponent(shareExtensionTraceFileName)
+        try? FileManager.default.removeItem(at: fileURL)
+    }
+
     /**
      * Check if shared photo ready flag is set
      * This flag is set by the Share Extension when image is ready

ios/App/TimeSafariShareExtension/ShareViewController.swift

@@ -17,12 +17,36 @@ class ShareViewController: UIViewController {
     private let shareExtensionLastStartKey = "shareExtensionLastStart"
     private let sharedImageFileName = "shared-image"
 
+    // TEMPORARY SHARE TARGET DIAGNOSTICS
+    private let shareExtensionTraceFileName = "share-extension-trace.log"
+
     /// Get the App Group container URL for storing shared files
     private var appGroupContainerURL: URL? {
         return FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroupIdentifier)
     }
 
+    // TEMPORARY SHARE TARGET DIAGNOSTICS
+    /// Append a single timestamped line to the Share Extension trace file in the
+    /// App Group container. Each line is prefixed with an ISO8601 timestamp.
+    /// Logging failures are intentionally ignored (diagnostics only).
+    private func appendTrace(_ message: String) {
+        guard let containerURL = appGroupContainerURL else { return }
+        let fileURL = containerURL.appendingPathComponent(shareExtensionTraceFileName)
+        let timestamp = ISO8601DateFormatter().string(from: Date())
+        let line = "\(timestamp) \(message)\n"
+        guard let data = line.data(using: .utf8) else { return }
+        if let handle = try? FileHandle(forWritingTo: fileURL) {
+            defer { try? handle.close() }
+            _ = try? handle.seekToEnd()
+            try? handle.write(contentsOf: data)
+        } else {
+            try? data.write(to: fileURL, options: .atomic)
+        }
+    }
+
     override func viewDidLoad() {
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("viewDidLoad START")
         if let userDefaults = UserDefaults(suiteName: appGroupIdentifier) {
             let timestamp = ISO8601DateFormatter().string(from: Date())
             userDefaults.set(timestamp, forKey: shareExtensionLastStartKey)
@@ -39,19 +63,29 @@ class ShareViewController: UIViewController {
         // Process image immediately without showing UI
         processAndOpenApp()
         print("[ShareTarget] viewDidLoad completed")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("viewDidLoad END")
     }
 
     private func processAndOpenApp() {
         print("[ShareTarget] processAndOpenApp started")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("processAndOpenApp START")
 
         // extensionContext is automatically available on UIViewController when used as extension principal class
         guard let context = extensionContext,
               let inputItems = context.inputItems as? [NSExtensionItem] else {
             print("[ShareTarget] processAndOpenApp failed: missing extensionContext or inputItems")
             print("[ShareTarget] completeRequest starting")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            appendTrace("completeRequest START")
             extensionContext?.completeRequest(returningItems: [], completionHandler: nil)
             print("[ShareTarget] completeRequest completed")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            appendTrace("completeRequest END")
             print("[ShareTarget] processAndOpenApp completed")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            appendTrace("processAndOpenApp END")
             return
         }
 
@@ -64,6 +98,8 @@ class ShareViewController: UIViewController {
             guard let self = self, let context = self.extensionContext else {
                 print("[ShareTarget] processAndOpenApp failed: self or extensionContext unavailable in completion")
                 print("[ShareTarget] processAndOpenApp completed")
+                // TEMPORARY SHARE TARGET DIAGNOSTICS
+                self?.appendTrace("processAndOpenApp END")
                 return
             }
 
@@ -78,23 +114,35 @@ class ShareViewController: UIViewController {
 
             // Complete immediately - no UI shown
             print("[ShareTarget] completeRequest starting")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            self.appendTrace("completeRequest START")
             context.completeRequest(returningItems: [], completionHandler: nil)
             print("[ShareTarget] completeRequest completed")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            self.appendTrace("completeRequest END")
             print("[ShareTarget] processAndOpenApp completed")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            self.appendTrace("processAndOpenApp END")
         }
     }
 
     private func setSharedPhotoReadyFlag() {
         print("[ShareTarget] setSharedPhotoReadyFlag started")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("setSharedPhotoReadyFlag START")
         guard let userDefaults = UserDefaults(suiteName: appGroupIdentifier) else {
             print("[ShareTarget] setSharedPhotoReadyFlag failed: UserDefaults unavailable for app group")
             print("[ShareTarget] setSharedPhotoReadyFlag completed")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            appendTrace("setSharedPhotoReadyFlag FAILURE")
             return
         }
         userDefaults.set(true, forKey: "sharedPhotoReady")
         userDefaults.synchronize()
         print("[ShareTarget] setSharedPhotoReadyFlag success")
         print("[ShareTarget] setSharedPhotoReadyFlag completed")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("setSharedPhotoReadyFlag SUCCESS")
     }
 
     private func processSharedImage(from items: [NSExtensionItem], completion: @escaping (Bool) -> Void) {
@@ -102,6 +150,8 @@ class ShareViewController: UIViewController {
             count + (item.attachments?.count ?? 0)
         }
         print("[ShareTarget] processSharedImage started attachmentCount=\(attachmentCount)")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("processSharedImage START")
 
         // Find the first image attachment
         for item in items {
@@ -120,6 +170,8 @@ class ShareViewController: UIViewController {
                 let shareId = UUID().uuidString
                 print("[ShareTarget] processSharedImage found image attachment shareId=\(shareId) UTType=\(UTType.image.identifier)")
                 print("[ShareTarget] share received shareId=\(shareId)")
+                // TEMPORARY SHARE TARGET DIAGNOSTICS
+                appendTrace("image attachment found shareId=\(shareId)")
 
                 // Try to load raw data first to preserve original format
                 // This preserves the original image format without conversion
@@ -134,6 +186,8 @@ class ShareViewController: UIViewController {
                     if let error = error {
                         print("[ShareTarget] processSharedImage failed: loadItem error shareId=\(shareId) error=\(error.localizedDescription)")
                         print("[ShareTarget] processSharedImage completed shareId=\(shareId) success=false")
+                        // TEMPORARY SHARE TARGET DIAGNOSTICS
+                        self.appendTrace("processSharedImage END success=false")
                         completion(false)
                         return
                     }
@@ -177,19 +231,27 @@ class ShareViewController: UIViewController {
                     guard let finalImageData = imageData else {
                         print("[ShareTarget] processSharedImage failed: no image data shareId=\(shareId)")
                         print("[ShareTarget] processSharedImage completed shareId=\(shareId) success=false")
+                        // TEMPORARY SHARE TARGET DIAGNOSTICS
+                        self.appendTrace("processSharedImage END success=false")
                         completion(false)
                         return
                     }
 
                     print("[ShareTarget] image loaded bytes=\(finalImageData.count) filename=\(fileName) shareId=\(shareId)")
+                    // TEMPORARY SHARE TARGET DIAGNOSTICS
+                    self.appendTrace("image loaded shareId=\(shareId) bytes=\(finalImageData.count)")
 
                     // Store image as file in App Group container
                     if self.storeImageData(finalImageData, fileName: fileName, shareId: shareId) {
                         print("[ShareTarget] processSharedImage completed shareId=\(shareId) success=true")
+                        // TEMPORARY SHARE TARGET DIAGNOSTICS
+                        self.appendTrace("processSharedImage END success=true")
                         completion(true)
                     } else {
                         print("[ShareTarget] processSharedImage failed: storeImageData returned false shareId=\(shareId)")
                         print("[ShareTarget] processSharedImage completed shareId=\(shareId) success=false")
+                        // TEMPORARY SHARE TARGET DIAGNOSTICS
+                        self.appendTrace("processSharedImage END success=false")
                         completion(false)
                     }
                 }
@@ -200,6 +262,8 @@ class ShareViewController: UIViewController {
         // No image found
         print("[ShareTarget] processSharedImage failed: no image attachment found attachmentCount=\(attachmentCount)")
         print("[ShareTarget] processSharedImage completed success=false")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("processSharedImage END success=false")
         completion(false)
     }
 
@@ -227,10 +291,14 @@ class ShareViewController: UIViewController {
     /// Returns true if successful, false otherwise
     private func storeImageData(_ imageData: Data, fileName: String, shareId: String) -> Bool {
         print("[ShareTarget] storeImageData started shareId=\(shareId) bytes=\(imageData.count) filename=\(fileName)")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("storeImageData START shareId=\(shareId)")
 
         guard let containerURL = appGroupContainerURL else {
             print("[ShareTarget] storeImageData failed: app group container unavailable shareId=\(shareId)")
             print("[ShareTarget] storeImageData completed shareId=\(shareId) success=false")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            appendTrace("storeImageData FAILURE shareId=\(shareId)")
             return false
         }
 
@@ -253,6 +321,8 @@ class ShareViewController: UIViewController {
         } catch {
             print("[ShareTarget] storeImageData failed: file write error shareId=\(shareId) error=\(error.localizedDescription)")
             print("[ShareTarget] storeImageData completed shareId=\(shareId) success=false")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            appendTrace("storeImageData FAILURE shareId=\(shareId)")
             return false
         }
         print("[ShareTarget] file stored shareId=\(shareId) originalFilename=\(originalFileName) storedFilename=\(storedFileName)")
@@ -261,6 +331,8 @@ class ShareViewController: UIViewController {
         guard let userDefaults = UserDefaults(suiteName: appGroupIdentifier) else {
             print("[ShareTarget] storeImageData failed: UserDefaults unavailable shareId=\(shareId)")
             print("[ShareTarget] storeImageData completed shareId=\(shareId) success=false")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            appendTrace("storeImageData FAILURE shareId=\(shareId)")
             return false
         }
 
@@ -276,16 +348,22 @@ class ShareViewController: UIViewController {
         print("[ShareTarget] metadata stored shareId=\(shareId) originalFilename=\(originalFileName) storedFilename=\(storedFileName)")
         print("[ShareTarget] storeImageData success shareId=\(shareId)")
         print("[ShareTarget] storeImageData completed shareId=\(shareId) success=true")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("storeImageData SUCCESS shareId=\(shareId)")
         return true
     }
 
     private func openMainApp() {
         print("[ShareTarget] openMainApp starting")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("openMainApp START")
 
         // Open the main app with minimal URL - app will detect shared data on activation
         guard let url = URL(string: "timesafari://") else {
             print("[ShareTarget] openMainApp failed: could not create timesafari:// URL")
             print("[ShareTarget] openMainApp completed")
+            // TEMPORARY SHARE TARGET DIAGNOSTICS
+            appendTrace("openMainApp FAILURE")
             return
         }
 
@@ -294,6 +372,8 @@ class ShareViewController: UIViewController {
             if let application = responder as? UIApplication {
                 application.open(url, options: [:], completionHandler: nil)
                 print("[ShareTarget] openMainApp completed via UIApplication")
+                // TEMPORARY SHARE TARGET DIAGNOSTICS
+                appendTrace("openMainApp SUCCESS")
                 return
             }
             responder = responder?.next
@@ -302,6 +382,8 @@ class ShareViewController: UIViewController {
         // Fallback: use extension context
         extensionContext?.open(url, completionHandler: nil)
         print("[ShareTarget] openMainApp completed via extensionContext fallback")
+        // TEMPORARY SHARE TARGET DIAGNOSTICS
+        appendTrace("openMainApp SUCCESS")
     }
 
 }

src/plugins/SharedImagePlugin.web.ts

@@ -8,6 +8,8 @@ import type {
   SharedImagePlugin,
   SharedImageResult,
   ShareExtensionDiagnostics,
+  // TEMPORARY SHARE TARGET DIAGNOSTICS
+  ShareExtensionTrace,
 } from "./definitions";
 
 export class SharedImagePluginWeb
@@ -33,4 +35,14 @@ export class SharedImagePluginWeb
       pendingShareExists: false,
     };
   }
+
+  // TEMPORARY SHARE TARGET DIAGNOSTICS
+  async getShareExtensionTrace(): Promise<ShareExtensionTrace> {
+    return { trace: "" };
+  }
+
+  // TEMPORARY SHARE TARGET DIAGNOSTICS
+  async clearShareExtensionTrace(): Promise<void> {
+    // Web platform doesn't support native sharing - no-op
+  }
 }

src/plugins/definitions.ts

@@ -16,6 +16,11 @@ export interface ShareExtensionDiagnostics {
   pendingShareExists: boolean;
 }
 
+// TEMPORARY SHARE TARGET DIAGNOSTICS
+export interface ShareExtensionTrace {
+  trace: string;
+}
+
 export interface SharedImagePlugin {
   /**
    * Get shared image data from native layer
@@ -34,4 +39,16 @@ export interface SharedImagePlugin {
    * Diagnostic snapshot of Share Extension startup and pending share state (iOS)
    */
   getShareExtensionDiagnostics(): Promise<ShareExtensionDiagnostics>;
+
+  // TEMPORARY SHARE TARGET DIAGNOSTICS
+  /**
+   * Read the raw Share Extension execution trace log (iOS)
+   */
+  getShareExtensionTrace(): Promise<ShareExtensionTrace>;
+
+  // TEMPORARY SHARE TARGET DIAGNOSTICS
+  /**
+   * Delete the Share Extension execution trace log if present (iOS)
+   */
+  clearShareExtensionTrace(): Promise<void>;
 }