Jog Controls Overhaul

Redesigned the robot's manual jog control system across the full stack — fixing a cluster of frontend bugs in touch event handling and a subtle real-time control issue where a smoothing filter caused incremental jogs to under-travel. The fix required tracing through the UI, the messaging layer, and the real-time trajectory pipeline.

Diagnosed a cluster of frontend touch-handling bugs in the jog controls — including duplicate events on touch devices, release handlers fighting in-flight motion commands, edge-of-deadband states being misinterpreted as stop commands, and a legacy speed multiplier that needed refactoring out.

Implemented a tap-vs-hold detection system: a short press triggers an incremental jog (single fixed-distance move), while a longer press triggers a continuous jog (robot moves until release). This unified interaction pattern replaced a previous system where tap and hold had separate, conflicting code paths. Pointer capture ensures reliable tracking even when the pointer leaves the joystick element bounds.

The backend bug was the most subtle — a smoothing filter sized for steady-state convergence interacted poorly with short single-command incremental moves, leaving the robot well short of the commanded position. The fix added a per-command smoothing-enable toggle to the trajectory buffer, disabled for incremental moves and preserved for continuous jog.