Add seated PSVR webcam 6DoF tracking

[Davidbkr03]

Summary

• Add an opt-in generic webcam tracker backend using Windows Media Foundation, stable device identities, exact native mode persistence, bounded latest-frame capture, and camera-control readback.
• Track the PSVR headset's built-in LED constellation with a deterministic correspondence/PnP solver, geometric quality gates, and recovery priors suitable for a seated, single-camera setup.
• Fuse optical translation and capture-time optical orientation with timestamped Morpheus IMU orientation so rendering keeps the headset's low-latency rotational updates while the camera corrects 6DoF position.
• Add configuration/protocol support, calibration-mode gating, config migration, operational diagnostics, deterministic tests, and a complete setup/hardware-validation guide.
• Preserve the existing PS3 Eye/controller tracking path; generic webcam discovery is allowlisted and disabled by default.

Reason

PSMoveServiceEx can read the PSVR headset sensors, but it did not provide a production path for tracking the headset's built-in LEDs through a normal webcam. This change supplies the missing optical position path and aligns it with the headset's own clocked IMU data for seated PC VR use.

Implementation

• Windows Media Foundation enumeration and asynchronous Source Reader capture.
• Stable symbolic-link-derived tracker IDs and explicit allowlisting.
• Exact video/calibration mode identity, progressive-mode selection, stride-aware BGR/MJPEG conversion, and normalized exposure/gain controls.
• Versioned nine-point PSVR LED model, configurable front-LED mask/intensity, contour extraction, bounded correspondence search, Hungarian assignment, PnP refinement, and reprojection/depth/geometry gates.
• 24-bit 1 MHz Morpheus sensor-clock unwrap and host-clock synchronization.
• Delayed-frame fusion using capture-time IMU alignment, current-IMU orientation advancement, position age compensation, duplicate/stale/future rejection, and clear tracking status diagnostics.
• Config Tool and protocol extensions with older-client/config compatibility.

Testing performed

• Fresh strict Linux build with GCC 13, CMake 3.28, OpenCV 4.6, and -Wall -Wextra -Werror -pedantic.
• ctest: 5/5 tests passed:
  • Morpheus sensor clock
  • point-cloud pose solver
  • optical/IMU fusion
  • video-source helpers
  • generic-webcam enumerator helpers
• Generated and compiled PSMoveProtocol.
• Compiled the feature-facing service objects available in the Linux environment, including the solver/fusion, HMD/tracker views and managers, Morpheus device path, PS3Eye tracker, generic enumerator, and non-Windows video-source path.
• Independent static audits found no remaining code-proven P0/P1 defects.

The full Linux service target remains blocked by an existing upstream/pinned-submodule mismatch: ControllerManager.cpp calls Gamepad_init(gamepad_api_xinput_only), while the pinned libstem exposes Gamepad_init() with no argument. That unrelated semantic mismatch was not papered over in this PR.

Documentation updated

• Add misc/PSVR_LED_TRACKING.md with architecture, configuration, calibration, diagnostics, test coverage, hardware acceptance gates, rollback, and iVRy handoff.
• Link the guide from README.md.

Remaining validation / why this is a draft

• Build the Windows-only Media Foundation and Config Tool paths with the repository's supported MSVC/Windows SDK toolchain.
• Run physical calibration and validate LED coordinates, camera intrinsics/distortion, PSVR IMU-to-optical axes, exposure/gain behavior, capture latency, occlusion recovery, and seated tracking volume.
• Verify the final pose is consumed correctly by the target iVRy/SteamVR runtime.

No PSVR, webcam, native Windows toolchain, or iVRy runtime was available for this implementation pass, so those hardware/runtime checks are intentionally not claimed.