Load type signatures for mruby

Load mruby class method signatures dynamically

Discovering mruby type landscape when starting a task in unfamiliar dynamic-typed codebases.

• · Target Ruby file
• · Optional class/method name
• · Command flags (--llm-nav, --llm-class, --llm-define)

• · Class list
• · Method signatures with types
• · Callers/callees graph

• · ti type checker installed
• · mruby project present

• · File not found
• · Incomplete type info
• · Truncated output from pipe commands

• · Multi-step workflow documented
• · Explicit warnings about output truncation