feat: refactor ball_bearing_info() to return struct (#1933)

[junhinhow]

Summary

• Change ball_bearing_info() return type from positional array to named struct
• Keys: type, trade_size, id, od, width, shielded, flanged, flange_diameter, flange_width
• Update ball_bearing() module to use struct_val() for field extraction
• Follows same pattern as screw_info(), nut_info() for API consistency

Test plan

• struct_val() correctly retrieves all fields (id, od, width, trade_size, type)
• ball_bearing() with trade_size renders correctly
• ball_bearing() with direct parameters still works
• Flanged bearings render correctly

🤖 Generated with Claude Code