feat: Initial implementation of FitTrack Report Generator

This commit introduces the initial version of the FitTrack Report Generator, a FastAPI application for analyzing workout files.

Key features include:
- Parsing of FIT, TCX, and GPX workout files.
- Analysis of power, heart rate, speed, and elevation data.
- Generation of summary reports and charts.
- REST API for single and batch workout analysis.

The project structure has been set up with a `src` directory for core logic, an `api` directory for the FastAPI application, and a `tests` directory for unit, integration, and contract tests.

The development workflow is configured to use Docker and modern Python tooling.

tests/unit/test_tcx_parser.py

@@ -0,0 +1,34 @@
+import pytest
+from unittest.mock import MagicMock, patch
+from src.core.file_parser import TcxParser, WorkoutData, WorkoutMetadata
+from datetime import datetime, timedelta
+
+@pytest.fixture
+def mock_tcx_parser():
+    # Patch the TCXParser class where it's imported in src.core.file_parser
+    with patch('src.core.file_parser.TCXParser') as mock_tcx_parser_class:
+        mock_tcx_instance = MagicMock()
+        mock_tcx_parser_class.return_value = mock_tcx_instance
+
+        mock_tcx_instance.started_at = datetime(2023, 1, 1, 10, 0, 0)
+        mock_tcx_instance.duration = 3600 # 1 hour
+        # Mock other attributes as needed for future tests
+
+        yield mock_tcx_parser_class
+
+def test_tcx_parser_initialization():
+    parser = TcxParser("dummy.tcx")
+    assert parser.file_path == "dummy.tcx"
+
+def test_tcx_parser_parse_method_returns_workout_data(mock_tcx_parser):
+    parser = TcxParser("dummy.tcx")
+    workout_data = parser.parse()
+
+    mock_tcx_parser.assert_called_once_with("dummy.tcx")
+
+    assert isinstance(workout_data, WorkoutData)
+    assert isinstance(workout_data.metadata, WorkoutMetadata)
+    assert workout_data.metadata.file_type == "TCX"
+    assert workout_data.metadata.start_time == datetime(2023, 1, 1, 10, 0, 0)
+    assert workout_data.metadata.duration == timedelta(seconds=3600)
+    assert workout_data.time_series_data.empty # Currently, no time series data is mocked