feat: Implement Task Dependencies

[aacevski]

Problem Statement

Complex projects often have tasks that depend on the completion of other tasks, but currently there's no way to represent these dependencies in Kaneo. This makes it difficult to plan work sequences and understand blockers.

Proposed Solution

Implement task dependency functionality that allows users to:

• Create predecessor/successor relationships between tasks
• Visualize dependencies in board and timeline views
• Receive notifications when blocking tasks are completed
• Filter tasks by dependency status (blocked, blocking, etc.)
• Detect and prevent circular dependencies

Alternative Solutions

• Using manual task linking without formal dependency tracking
• Using task descriptions to note dependencies
• Creating separate views for dependent task sequences

Relevant Context

Task dependencies are essential for planning complex projects where work must be completed in a specific sequence. This feature is standard in advanced project management tools.

Does this feature align with Kaneo's focus on simplicity?

Yes, because it adds important planning context without cluttering the interface. Dependencies will be accessible when needed but won't overwhelm the main task views.