Add dependency analysis and blast radius tool

[patmakesapps]

Problem

Before changing a function, users need to know what will break. There is no way to see the blast radius of a change.

Proposed Solution

• Use existing find_imports tool to trace dependencies
• Visualize dependency graph
• Warn about breaking changes
• Show "safe to modify" vs "proceed with caution" indicators

Acceptance Criteria

• Can show all files affected by changing a function
• Dependency graph is accurate
• Warnings for high-impact changes
• Uses existing code intel tools