Implement database storage with optional cloud support

[chriscarrollsmith]

This issue consolidates #19 (Store in database rather than JSON) and #9 (Optional cloud storage for orchestration across containers).

Current Implementation

Currently, TaskManager stores data in JSON files using the file system, with platform-specific paths.

Proposed Changes

1. Database Storage:

   • Use SQLite by default (replacing JSON files) for better reliability and performance
   • Provide a configurable adapter pattern for database access
   • Support for concurrent connections

2. Optional Cloud Storage:

   • Add capability to store data in cloud services
   • Enable orchestration across multiple containers
   • Allow configuration via environment variables or config file
   • Support synchronization between local and remote storage

Benefits

• Better data integrity with database transactions
• Support for multiple instances sharing the same data
• Scalability across containers
• Configurable storage options based on user needs

Implementation Notes

• Create a pluggable storage adapter system
• SQLite will be the default (no external services required)
• Add optional support for cloud services like PostgreSQL, MySQL, etc.
• Ensure backward compatibility with existing JSON format