Initial implementation of Fantasy Hockey watchOS app

Implemented complete TCA architecture for iOS and watchOS targets:
- Authentication flow (Sign in with Apple + Yahoo OAuth)
- OAuth token management with iCloud Key-Value Storage
- Yahoo Fantasy Sports API client with async/await
- Watch Connectivity for iPhone ↔ Watch data sync
- Complete UI for both iPhone and Watch platforms

Core features:
- Matchup score display
- Category breakdown with win/loss/tie indicators
- Roster status tracking
- Manual refresh functionality
- Persistent data caching on Watch

Technical stack:
- The Composable Architecture for state management
- Swift Concurrency (async/await, actors)
- WatchConnectivity framework
- Sign in with Apple
- OAuth 2.0 authentication flow

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

FantasyWatch/Shared/Networking/YahooAPI/XMLResponseDecoder.swift

@@ -0,0 +1,61 @@
+//
+//  XMLResponseDecoder.swift
+//  FantasyWatch
+//
+//  Created by Claude Code
+//
+
+import Foundation
+
+final class XMLResponseDecoder: NSObject, XMLParserDelegate {
+    private var currentElement = ""
+    private var currentValue = ""
+    private var elementStack: [String] = []
+    private var dataDict: [String: Any] = [:]
+    private var arrayStack: [[String: Any]] = []
+
+    func decode<T: Decodable>(_ type: T.Type, from data: Data) throws -> T {
+        let parser = XMLParser(data: data)
+        parser.delegate = self
+
+        guard parser.parse() else {
+            throw NetworkError.decodingError(
+                NSError(domain: "XMLDecoder", code: -1, userInfo: [NSLocalizedDescriptionKey: "Failed to parse XML"])
+            )
+        }
+
+        let jsonData = try JSONSerialization.data(withJSONObject: dataDict)
+        return try JSONDecoder().decode(T.self, from: jsonData)
+    }
+
+    func parser(_ parser: XMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String] = [:]) {
+        currentElement = elementName
+        elementStack.append(elementName)
+        currentValue = ""
+    }
+
+    func parser(_ parser: XMLParser, foundCharacters string: String) {
+        currentValue += string.trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+
+    func parser(_ parser: XMLParser, didEndElement elementName: String, namespaceURI: String?, qualifiedName qName: String?) {
+        elementStack.removeLast()
+
+        if !currentValue.isEmpty {
+            let path = elementStack.joined(separator: ".")
+            dataDict[elementName] = currentValue
+
+            if !path.isEmpty {
+                dataDict[path + "." + elementName] = currentValue
+            }
+        }
+
+        currentValue = ""
+    }
+}
+
+// NOTE: This is a simplified XML decoder for POC purposes.
+// The Yahoo Fantasy API returns complex nested XML structures.
+// For production, we would need to implement more sophisticated parsing
+// that handles arrays, nested objects, and the specific Yahoo XML schema.
+// For now, we will parse the specific endpoints we need with custom logic.