Prevent preference defaults startup crash

Sources/KeyPathAppKit/Services/Configuration/PreferencesService.swift

@@ -166,7 +166,7 @@
     }
 }
 
 /// Manages KeyPath application preferences and settings
 // SAFETY: @unchecked Sendable — all mutable state is backed by UserDefaults (thread-safe)
 // and the shared instance is confined to @MainActor. @Observable macro prevents conforming
 // to Sendable directly; @unchecked bridges the gap.
@@ -179,7 +179,13 @@
     static var canonicalDefaults: UserDefaults {
         TestEnvironment.isRunningTests
             ? .standard
-            : UserDefaults(suiteName: "com.keypath.KeyPath")!
+            : canonicalDefaults(using: UserDefaults(suiteName: "com.keypath.KeyPath"))
+    }
+
+    /// The suite can be unavailable during early app launch. Preferences must
+    /// still initialize so launchd does not restart the app in a crash loop.
+    static func canonicalDefaults(using suiteDefaults: UserDefaults?) -> UserDefaults {
+        suiteDefaults ?? .standard
     }
 
     static let leaderKeyPreferenceKey = "KeyPath.LeaderKey.Preference"

Tests/KeyPathTests/PreferencesServiceTests.swift

@@ -3,6 +3,16 @@ import XCTest
 
 @MainActor
 final class PreferencesServiceTests: XCTestCase {
+    func testCanonicalDefaultsFallsBackToStandardWhenSuiteIsUnavailable() {
+        let key = "PreferencesServiceTests.canonicalDefaultsFallback"
+        let defaults = PreferencesService.canonicalDefaults(using: nil)
+        defer { UserDefaults.standard.removeObject(forKey: key) }
+
+        defaults.set(true, forKey: key)
+
+        XCTAssertTrue(UserDefaults.standard.bool(forKey: key))
+    }
+
     // MARK: - Port Validation
 
     func testIsValidPort_AcceptsUserPorts() {