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.

examples/GarminSync/workflows.md

@@ -0,0 +1,100 @@
+# GarminSync Workflows
+
+## Migration Workflow
+
+### Purpose
+Add new columns to database and populate with activity metrics
+
+### Trigger
+`python cli.py migrate`
+
+### Steps
+1. Add required columns to activities table:
+   - activity_type (TEXT)
+   - duration (INTEGER)
+   - distance (REAL)
+   - max_heart_rate (INTEGER)
+   - avg_power (REAL)
+   - calories (INTEGER)
+2. For each activity:
+   - Parse metrics from local FIT/XML files
+   - Fetch from Garmin API if local files missing
+   - Update database fields
+3. Commit changes
+4. Report migration status
+
+### Error Handling
+- Logs errors per activity
+- Marks unprocessable activities as "Unknown"
+- Continues processing other activities on error
+
+## Sync Workflow
+
+### Purpose
+Keep local database synchronized with Garmin Connect
+
+### Triggers
+- CLI commands (`list`, `download`)
+- Scheduled daemon (every 6 hours by default)
+- Web UI requests
+
+### Core Components
+- `sync_database()`: Syncs activity metadata
+- `download()`: Fetches missing FIT files
+- Daemon: Background scheduler and web UI
+
+### Process Flow
+1. Authenticate with Garmin API
+2. Fetch latest activities
+3. For each activity:
+   - Parse metrics from FIT/XML files
+   - Fetch from Garmin API if local files missing
+   - Update database fields
+4. Download missing activity files
+5. Update sync timestamps
+6. Log operations
+
+### Database Schema
+```mermaid
+erDiagram
+    activities {
+        integer activity_id PK
+        string start_time
+        string activity_type
+        integer duration
+        float distance
+        integer max_heart_rate
+        integer avg_heart_rate
+        float avg_power
+        integer calories
+        string filename
+        boolean downloaded
+        string created_at
+        string last_sync
+    }
+    
+    daemon_config {
+        integer id PK
+        boolean enabled
+        string schedule_cron
+        string last_run
+        string next_run
+        string status
+    }
+    
+    sync_logs {
+        integer id PK
+        string timestamp
+        string operation
+        string status
+        string message
+        integer activities_processed
+        integer activities_downloaded
+    }
+```
+
+### Key Notes
+- Data directory: `data/` (configurable via DATA_DIR)
+- Web UI port: 8080 (default)
+- Downloaded files: `activity_{id}_{timestamp}.fit`
+- Metrics include: heart rate, power, calories, distance