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.

specs/001-create-a-new/plan.md

@@ -0,0 +1,108 @@
+# Implementation Plan: [FEATURE]
+
+**Branch**: `[###-feature-name]` | **Date**: [DATE] | **Spec**: [link]
+**Input**: Feature specification from `/specs/[###-feature-name]/spec.md`
+
+**Note**: This template is filled in by the `/speckit.plan` command. See `.specify/templates/commands/plan.md` for the execution workflow.
+
+## Summary
+
+[Extract from feature spec: primary requirement + technical approach from research]
+
+## Technical Context
+
+<!--
+  ACTION REQUIRED: Replace the content in this section with the technical details
+  for the project. The structure here is presented in advisory capacity to guide
+  the iteration process.
+-->
+
+**Language/Version**: Python 3.11  
+**Primary Dependencies**: FastAPI, pandas, numpy, scipy, matplotlib, fitparse, tcxparser, gpxpy  
+**Storage**: PostgreSQL (for user data and analysis results)  
+**Testing**: pytest  
+**Target Platform**: Linux server  
+**Project Type**: web  
+**Performance Goals**: Analysis of a typical 2-hour workout file MUST complete in under 30 seconds; processing a batch of 100 workout files concurrently without generating errors or significant performance degradation.  
+**Constraints**: Public API (no authentication); errors reported as JSON objects; best effort service availability.  
+**Scale/Scope**: Batch analysis of up to 100 workout files concurrently; configurable FTP per user account.
+
+## Constitution Check
+
+*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*
+
+| Principle | Status | Justification (if violation) |
+|---|---|---|
+| I. Library-First | Aligned | Core analysis logic will be implemented as a reusable library. |
+| II. CLI Interface | VIOLATION | The primary interface is an API, not a CLI. Justification: The feature is designed as a web service with API endpoints for integration. A CLI could be added later if needed for specific use cases, but it's not the primary requirement for this feature. |
+| III. Test-First (NON-NEGOTIABLE) | Aligned | User scenarios and acceptance criteria are defined, supporting a test-first approach. |
+| IV. Integration Testing | Aligned | API endpoints and batch processing necessitate integration tests. |
+| V. Observability | Aligned | Error reporting and service availability imply the need for observability. |
+| VI. Versioning & Breaking Changes | Aligned | Will consider API versioning as part of the design. |
+| VII. Simplicity | Aligned | Focus on core analysis functionality. |
+
+## Project Structure
+
+### Documentation (this feature)
+
+```
+specs/[###-feature]/
+├── plan.md              # This file (/speckit.plan command output)
+├── research.md          # Phase 0 output (/speckit.plan command)
+├── data-model.md        # Phase 1 output (/speckit.plan command)
+├── quickstart.md        # Phase 1 output (/speckit.plan command)
+├── contracts/           # Phase 1 output (/speckit.plan command)
+└── tasks.md             # Phase 2 output (/speckit.tasks command - NOT created by /speckit.plan)
+```
+
+### Source Code (repository root)
+
+```
+src/
+├── core/
+│   ├── batch_processor.py
+│   ├── chart_generator.py
+│   ├── file_parser.py
+│   ├── logger.py
+│   ├── report_generator.py
+│   ├── workout_analyzer.py
+│   └── workout_data.py
+├── db/
+│   ├── models.py
+│   └── session.py
+└── utils/
+    └── zone_calculator.py
+
+api/
+├── routers/
+│   └── analysis.py
+├── main.py
+└── schemas.py
+
+tests/
+├── unit/
+│   ├── test_batch_processor.py
+│   ├── test_chart_generator.py
+│   ├── test_fit_parser.py
+│   ├── test_gpx_parser.py
+│   ├── test_tcx_parser.py
+│   └── test_workout_data.py
+├── integration/
+└── contract/
+    ├── test_analyze_workout_api.py
+    ├── test_batch_analysis_api.py
+    └── test_charts_api.py
+├── performance/
+│   └── test_performance.py
+```
+
+**Structure Decision**: The project will use a `src/` directory for core logic, `api/` for the FastAPI application, and `tests/` for all testing types. This aligns with a modular web application structure.
+
+## Complexity Tracking
+
+*Fill ONLY if Constitution Check has violations that must be justified*
+
+| Violation | Why Needed | Simpler Alternative Rejected Because |
+|-----------|------------|-------------------------------------|
+| [e.g., 4th project] | [current need] | [why 3 projects insufficient] |
+| [e.g., Repository pattern] | [specific problem] | [why direct DB access insufficient] |