Revert to 0.4.x, add Safari support

package.json

@@ -5,8 +5,8 @@
   "main": "src/popup/App.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
-    "build": "webpack-dev-server",
-    "build:prod": "webpack -p"
+    "dev": "webpack-dev-server",
+    "build": "webpack -p"
   },
   "keywords": [],
   "author": "",

safari/Canvas+/Canvas+ Extension/Info.plist

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>NSExtension</key>
+	<dict>
+		<key>NSExtensionPointIdentifier</key>
+		<string>com.apple.Safari.web-extension</string>
+		<key>NSExtensionPrincipalClass</key>
+		<string>$(PRODUCT_MODULE_NAME).SafariWebExtensionHandler</string>
+	</dict>
+</dict>
+</plist>

safari/Canvas+/Canvas+ Extension/SafariWebExtensionHandler.swift

@@ -0,0 +1,42 @@
+//
+//  SafariWebExtensionHandler.swift
+//  Canvas+ Extension
+//
+//  Created by Reese Armstrong on 2025-10-12.
+//
+
+import SafariServices
+import os.log
+
+class SafariWebExtensionHandler: NSObject, NSExtensionRequestHandling {
+
+    func beginRequest(with context: NSExtensionContext) {
+        let request = context.inputItems.first as? NSExtensionItem
+
+        let profile: UUID?
+        if #available(iOS 17.0, macOS 14.0, *) {
+            profile = request?.userInfo?[SFExtensionProfileKey] as? UUID
+        } else {
+            profile = request?.userInfo?["profile"] as? UUID
+        }
+
+        let message: Any?
+        if #available(iOS 15.0, macOS 11.0, *) {
+            message = request?.userInfo?[SFExtensionMessageKey]
+        } else {
+            message = request?.userInfo?["message"]
+        }
+
+        os_log(.default, "Received message from browser.runtime.sendNativeMessage: %@ (profile: %@)", String(describing: message), profile?.uuidString ?? "none")
+
+        let response = NSExtensionItem()
+        if #available(iOS 15.0, macOS 11.0, *) {
+            response.userInfo = [ SFExtensionMessageKey: [ "echo": message ] ]
+        } else {
+            response.userInfo = [ "message": [ "echo": message ] ]
+        }
+
+        context.completeRequest(returningItems: [ response ], completionHandler: nil)
+    }
+
+}