Fix empty AIWorkoutGenerator.swift and remove duplicate directory structure

Dropped/Models/AIWorkoutGenerator.swift

@@ -0,0 +1,82 @@
+
+//  AIWorkoutGenerator.swift
+//  Dropped
+//
+//  Service for generating structured cycling workouts using the OpenAI API.
+//
+//  - Handles prompt construction, API requests, and response parsing.
+//  - Designed for use by the WorkoutGeneratorViewModel.
+//
+//  Edge Cases: Handles API/network errors and invalid responses.
+//  Limitations: Assumes OpenAI API key is available and valid.
+
+import Foundation
+
+/// Error types for AIWorkoutGenerator
+enum AIWorkoutGeneratorError: Error {
+    case networkError(Error)
+    case invalidResponse
+    case apiError(String)
+}
+
+/// Service responsible for generating workouts using OpenAI's API.
+/// - Usage: Call `generateWorkout` with user FTP and selected WorkoutType.
+final class AIWorkoutGenerator {
+    private let apiKey: String
+    private let endpoint = URL(string: "https://api.openai.com/v1/chat/completions")!
+    private let model = "gpt-3.5-turbo"
+
+    /// Initialize with OpenAI API key
+    init(apiKey: String) {
+        self.apiKey = apiKey
+    }
+
+    /// Generates a structured workout using OpenAI
+    /// - Parameters:
+    ///   - ftp: User's Functional Threshold Power (watts)
+    ///   - type: Selected WorkoutType
+    ///   - completion: Callback with result (JSON string or error)
+    func generateWorkout(ftp: Int, type: WorkoutType, completion: @escaping (Result<String, AIWorkoutGeneratorError>) -> Void) {
+        let prompt = Self.makePrompt(ftp: ftp, type: type)
+        let requestBody: [String: Any] = [
+            "model": model,
+            "messages": [
+                ["role": "system", "content": "You are a cycling coach AI. Output only valid JSON."],
+                ["role": "user", "content": prompt]
+            ]
+        ]
+        guard let body = try? JSONSerialization.data(withJSONObject: requestBody) else {
+            completion(.failure(.invalidResponse))
+            return
+        }
+        var request = URLRequest(url: endpoint)
+        request.httpMethod = "POST"
+        request.setValue("Bearer \(apiKey)", forHTTPHeaderField: "Authorization")
+        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+        request.httpBody = body
+        let task = URLSession.shared.dataTask(with: request) { data, response, error in
+            if let error = error {
+                completion(.failure(.networkError(error)))
+                return
+            }
+            guard let data = data,
+                  let json = try? JSONSerialization.jsonObject(with: data) as? [String: Any],
+                  let choices = json["choices"] as? [[String: Any]],
+                  let message = choices.first?["message"] as? [String: Any],
+                  let content = message["content"] as? String else {
+                completion(.failure(.invalidResponse))
+                return
+            }
+            completion(.success(content))
+        }
+        task.resume()
+    }
+
+    /// Constructs the AI prompt for workout generation
+    private static func makePrompt(ftp: Int, type: WorkoutType) -> String {
+        """
+        Generate a structured cycling workout for a rider with FTP \(ftp) watts. Workout type: \(type.displayName).
+        Output JSON with fields: title, summary, intervals (array of {duration_minutes, target_watts, description}), and total_duration_minutes.
+        """
+    }
+}