Add test generation tool

[patmakesapps]

Problem

When writing code, there is no way to automatically generate tests. A test generation tool would save time and make codebases more robust.

Proposed Solution

• Analyze function signatures and docstrings
• Generate pytest or unittest boilerplate
• Include edge cases and typical usage examples
• Support "generate tests for this file" command or auto-trigger

Acceptance Criteria

• Can generate test files for supported languages
• Produces valid pytest-compatible tests
• Includes edge cases and typical usage
• Generated tests are runnable out of the box