Add O6 web controller

[JesseSChang]

Summary

• add a browser-based slider UI for controlling LinkerHand O6 position and torque
• add a C++ stdin-to-CAN bridge with live joint-position readback
• register the bridge in the CMake example source list

Why

This provides a lightweight local control surface for the O6 hand without additional Python dependencies. The Python server launches the compiled bridge and exposes pose, torque, trigger, preset, and measured-position controls in a browser.

Impact

The new controller is opt-in and does not change existing SDK behavior. It supports left and right O6 hands and builds as the o6_web_bridge example target.

Validation

• configured the project with examples and tests enabled
• built the o6_web_bridge CMake target successfully
• parsed web/o6_web.py with Python's AST parser
• ran python3 web/o6_web.py --help
• ran git diff --check
• scanned the new files for credential-like content

Hardware actuation was intentionally not exercised during validation.