Add the watchOS app and complication targets

The companion dropdown in Xcode's target template came up empty, which left
both bundle identifiers starting with a bare dot and
WKCompanionAppBundleIdentifier as an empty string. Both are set explicitly
here, along with the App Group entitlements and watchOS 26 as the floor.

The iOS app had no Embed Watch Content phase, so the watch app would have built
and never shipped. Added, with the matching target dependency: the product now
lands at Calendarr iOS.app/Watch/CalendarrWatch.app with the complications
inside it.

Folders follow what they contain: CalendarrWatch is the app,
CalendarrWatchComplications the extension. Xcode had them the other way round.

Package.resolved is now tracked. It pins AppAuth, whose version drift is what
produced the two compile errors fixed in 75a6a5b.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

CalendarrWatchUITests/CalendarrWatch_Watch_AppUITests.swift

@@ -0,0 +1,43 @@
+//
+//  CalendarrWatch_Watch_AppUITests.swift
+//  CalendarrWatch Watch AppUITests
+//
+//  Created by Guido Schmit on 11.09.2026.
+//
+
+import XCTest
+
+final class CalendarrWatch_Watch_AppUITests: XCTestCase {
+
+    override func setUpWithError() throws {
+        // Put setup code here. This method is called before the invocation of each test method in the class.
+
+        // In UI tests it is usually best to stop immediately when a failure occurs.
+        continueAfterFailure = false
+
+        // In UI tests it’s important to set the initial state - such as interface orientation - required for your tests before they run. The setUp method is a good place to do this.
+    }
+
+    override func tearDownWithError() throws {
+        // Put teardown code here. This method is called after the invocation of each test method in the class.
+    }
+
+    @MainActor
+    func testExample() throws {
+        // UI tests must launch the application that they test.
+        let app = XCUIApplication()
+        app.launch()
+
+        // Use XCTAssert and related functions to verify your tests produce the correct results.
+        // XCUIAutomation Documentation
+        // https://developer.apple.com/documentation/xcuiautomation
+    }
+
+    @MainActor
+    func testLaunchPerformance() throws {
+        // This measures how long it takes to launch your application.
+        measure(metrics: [XCTApplicationLaunchMetric()]) {
+            XCUIApplication().launch()
+        }
+    }
+}