[PCrnjak]

Adds a robot-independent relative Cartesian control engine, an explicit adapter contract, and a browser lab that sends targets to a simulated Cartesian arm. Applications supply their own robot reference, workspace, speed limits, capabilities, and SDK callbacks; joint-only robots supply kinematics in their adapter.

Behavior:

• Starts disarmed. Explicit calibration anchors the selected hand to robot feedback or an explicit reference. Clutch holds output; resume re-anchors on a fresh frame without emitting a jump target.
• Hand loss/identity changes, stale frames, timing/clock gaps, and device changes latch loss and invoke adapter hold. Returning frames do not rearm. Adapter failures preserve their cause and latch a fault; close releases resources even when hold fails.
• Supports signed axes, arbitrary quaternion frame alignment, independent gains/axis locks, time-based smoothing/deadband, Cartesian speed/workspace bounds, optional relative rotation/angular limits, and normalized grab/pinch gripper mapping.
• Includes CallbackAdapter and SimulatedArm with immediate Cartesian feedback, strict TOML settings, typed command/session metadata, and a runnable SDK-boundary example.
• source-leap teleop --demo opens the packaged local lab; removing --demo uses the Leap controller with the same simulated output. The viewer shows tool pose/path, gripper, tracking health, and arm/clutch/disarm controls. Headless and recorded-input modes are also available. No web framework, robot SDK, numerical dependency, or JavaScript build is required for users.

Validation:

• The installed wheel passed 180 tests on each Windows CPython 3.10.11, 3.11.9, 3.12.10, 3.13.17, 3.14.10, and 3.15.2, with live reads in both tracking modes and dependency checks.
• Each version processed the existing 1,047-frame real recording containing 50 complete left-hand samples. A clutch/resume cycle generated 18 simulated targets within workspace/speed bounds; no commands followed hand loss.
• Deterministic behavioral tests cover no-output states, loss/rearm, clutch continuity, a 500-frame bounded trajectory, quaternion composition/frame alignment, smoothing/gripper/rate limits, capabilities, callback faults and cleanup, packaged viewer assets/actions, and CLI telemetry.
• Ruff, strict Twine metadata, wheel/sdist builds, artifact-content checks, JavaScript syntax, a runnable callback example, and Chrome UI checks passed locally. Platform CI runs on this PR.

This branch builds on the latest-frame API in #4. Source version is 0.1.0b3 development; no b3 publication is requested here. The engine/runtime download is unchanged. The lab has no joint/dynamics model, and no physical robot was commanded. Clean-Windows driver installation and Linux/macOS controller hardware remain external validation work. See docs/TELEOPERATION.md.

The local viewer uses an exclusive Windows listener. A regression test rejects a second lab on the same port, preventing competing sessions from sharing an address.