Fix Sendable warning in AppleMailError by dropping the NSDictionary payload

appleScriptError carried the raw NSDictionary from NSAppleScript's error
out-param, which isn't Sendable and got flagged once the type crossed an
async boundary. Extract just the two fields actually used (errorNumber,
errorMessage) into plain Int/String instead.

oAI/Services/AppleMailService.swift

@@ -37,9 +37,9 @@ struct MailSearchResult: Sendable, Equatable {
     let attachmentCount: String
 }
 
-enum AppleMailError: Error {
+enum AppleMailError: Error, Sendable {
     case scriptNotCompiled
-    case appleScriptError(NSDictionary)
+    case appleScriptError(number: Int, message: String)
 }
 
 @Observable
@@ -320,7 +320,9 @@ final class AppleMailService {
                 var errorDict: NSDictionary?
                 let result = script.executeAppleEvent(event, error: &errorDict)
                 if let errorDict {
-                    continuation.resume(returning: .failure(.appleScriptError(errorDict)))
+                    let number = (errorDict[NSAppleScript.errorNumber] as? Int) ?? 0
+                    let message = (errorDict[NSAppleScript.errorMessage] as? String) ?? "Unknown error"
+                    continuation.resume(returning: .failure(.appleScriptError(number: number, message: message)))
                 } else {
                     continuation.resume(returning: .success(result))
                 }
@@ -358,9 +360,7 @@ final class AppleMailService {
         return results
     }
 
-    nonisolated static func mapAppleScriptError(_ errorInfo: NSDictionary) -> String {
-        let number = (errorInfo[NSAppleScript.errorNumber] as? Int) ?? 0
-        let message = (errorInfo[NSAppleScript.errorMessage] as? String) ?? "Unknown error"
+    nonisolated static func mapAppleScriptError(number: Int, message: String) -> String {
         switch number {
         case -1743:
             return "Confab is not authorized to control Mail.app. Grant access in System Settings \u{2192} Privacy & Security \u{2192} Automation \u{2192} Confab \u{2192} Mail, then try again."
@@ -375,8 +375,8 @@ final class AppleMailService {
         switch error {
         case .scriptNotCompiled:
             return ["error": "Mail integration failed to initialize (AppleScript compile error)."]
-        case .appleScriptError(let dict):
-            return ["error": mapAppleScriptError(dict)]
+        case .appleScriptError(let number, let message):
+            return ["error": mapAppleScriptError(number: number, message: message)]
         }
     }
 
@@ -629,8 +629,8 @@ final class AppleMailService {
             switch error {
             case .scriptNotCompiled:
                 message = "Mail integration failed to initialize (AppleScript compile error)."
-            case .appleScriptError(let dict):
-                message = Self.mapAppleScriptError(dict)
+            case .appleScriptError(let number, let msg):
+                message = Self.mapAppleScriptError(number: number, message: msg)
             }
             return .failure(NSError(domain: "AppleMailService", code: 1, userInfo: [NSLocalizedDescriptionKey: message]))
         }

oAITests/AppleMailServiceTests.swift

@@ -85,32 +85,20 @@ struct AppleMailServiceTests {
 
     @Test("mapAppleScriptError maps -1743 to an Automation-permission message")
     func mapsNotAuthorizedError() {
-        let dict: NSDictionary = [
-            NSAppleScript.errorNumber: -1743,
-            NSAppleScript.errorMessage: "Not authorized"
-        ]
-        let message = AppleMailService.mapAppleScriptError(dict)
+        let message = AppleMailService.mapAppleScriptError(number: -1743, message: "Not authorized")
         #expect(message.contains("not authorized"))
         #expect(message.contains("Automation"))
     }
 
     @Test("mapAppleScriptError maps -600 to a Mail-not-available message")
     func mapsApplicationNotRunningError() {
-        let dict: NSDictionary = [
-            NSAppleScript.errorNumber: -600,
-            NSAppleScript.errorMessage: "Application isn't running"
-        ]
-        let message = AppleMailService.mapAppleScriptError(dict)
+        let message = AppleMailService.mapAppleScriptError(number: -600, message: "Application isn't running")
         #expect(message.contains("not available"))
     }
 
     @Test("mapAppleScriptError falls back to a generic formatted message for unknown error numbers")
     func mapsGenericError() {
-        let dict: NSDictionary = [
-            NSAppleScript.errorNumber: -1234,
-            NSAppleScript.errorMessage: "Something odd happened"
-        ]
-        let message = AppleMailService.mapAppleScriptError(dict)
+        let message = AppleMailService.mapAppleScriptError(number: -1234, message: "Something odd happened")
         #expect(message.contains("-1234"))
         #expect(message.contains("Something odd happened"))
     }