ci: update vcpkg commit to 2026.03.18 to fix Windows build

The pinned vcpkg commit referenced msys2-runtime-3.5.3-3 which is now
404 on all mirrors, causing the abseil dependency of opencv4 to fail.
Updated to vcpkg 2026.03.18 (c3867e7) which uses current package versions.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Geekgineer

.github/workflows/ci.yml

@@ -105,7 +105,7 @@ jobs:
     - name: Setup vcpkg
       uses: lukka/run-vcpkg@v11
       with:
-        vcpkgGitCommitId: 'c82f74667287d3dc386bce81e44964370c91a289'
+        vcpkgGitCommitId: 'c3867e714dd3a51c272826eea77267876517ed99'
 
     - name: Install dependencies
       run: |

CLAUDE.md

@@ -0,0 +1,141 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+**motcpp** is a modern C++ multi-object tracking (MOT) library implementing 10 state-of-the-art tracking algorithms (SORT, ByteTrack, OC-SORT, DeepOC-SORT, StrongSORT, BoT-SORT, BoostTrack, HybridSORT, UCMCTrack, OracleTrack). It is a C++ port of the Python BoxMOT library, targeting 10–100x speed improvements over Python equivalents.
+
+**License**: AGPL-3.0  
+**Requires**: C++17, CMake 3.20+, OpenCV 4.x, Eigen3, yaml-cpp  
+**Optional**: ONNX Runtime (ReID features), spdlog, GoogleTest (auto-fetched)
+
+## Build Commands
+
+```bash
+# Standard build
+cmake -B build -DCMAKE_BUILD_TYPE=Release
+cmake --build build -j$(nproc)
+
+# Build with tests (default: ON)
+cmake -B build -DMOTCPP_BUILD_TESTS=ON -DCMAKE_BUILD_TYPE=Debug
+cmake --build build -j$(nproc)
+
+# Run tests
+cd build && ctest --output-on-failure
+
+# Run a single test binary
+./build/tests/motcpp_tests --gtest_filter=TestSuiteName.TestCaseName
+
+# Coverage report
+cmake -B build -DMOTCPP_COVERAGE=ON
+cmake --build build --target coverage
+# Output: build/coverage_report/index.html
+
+# Build shared library
+cmake -B build -DBUILD_SHARED_LIBS=ON
+
+# Disable ONNX (motion-only trackers)
+cmake -B build -DMOTCPP_ENABLE_ONNX=OFF
+```
+
+**Key CMake options**:
+| Option | Default | Purpose |
+|--------|---------|---------|
+| `MOTCPP_BUILD_TESTS` | ON | GoogleTest unit tests |
+| `MOTCPP_BUILD_BENCHMARKS` | OFF | Benchmark targets |
+| `MOTCPP_BUILD_EXAMPLES` | ON | Example binaries |
+| `MOTCPP_BUILD_TOOLS` | ON | `motcpp_eval` CLI tool |
+| `MOTCPP_ENABLE_ONNX` | ON | ONNX Runtime for ReID |
+| `MOTCPP_COVERAGE` | OFF | gcov/lcov coverage |
+| `BUILD_SHARED_LIBS` | OFF | Static by default |
+
+## Architecture
+
+### Data Flow
+
+```
+Detections (N×6: x1,y1,x2,y2,conf,cls)
+         ↓
+   BaseTracker::update()
+         ↓
+  ┌──────────────────────────────────┐
+  │  1. Pre-process & validate      │
+  │  2. Predict existing tracks     │
+  │  3. Compute cost matrix         │
+  │     (IoU / appearance / hybrid) │
+  │  4. Hungarian assignment        │
+  │  5. Update matched tracks       │
+  │  6. Birth/death track states    │
+  └──────────────────────────────────┘
+         ↓
+Tracks (M×8: x1,y1,x2,y2,id,conf,cls,det_idx)
+```
+
+### Key Abstractions
+
+**`BaseTracker`** (`include/motcpp/tracker.hpp`, `src/tracker.cpp`)  
+Abstract base class for all trackers. Defines `update(dets, img)` and `reset()`. Manages per-class tracking, input validation, and visualization utilities. All 10 trackers inherit from this.
+
+**Motion Models** (`include/motcpp/motion/`, `src/motion/`)  
+- `KalmanFilterXYSR` — state: [x, y, scale, aspect ratio]; used by SORT, OC-SORT, BoostTrack  
+- `KalmanFilterXYAH` — state: [x, y, aspect ratio, height]; used by ByteTrack, StrongSORT, OracleTrack  
+- `UCMCKalmanFilter` — ground-plane model for camera motion compensation  
+- `BaseKalmanFilter` — common interface: `initiate`, `predict`, `update`, `project`
+
+**Association** (`include/motcpp/utils/`, `src/utils/`)  
+- `iou.hpp` — IoU, GIoU, DIoU, CIoU computations  
+- `matching.hpp` — Hungarian algorithm (linear assignment), cascade matching  
+- `association.hpp` — Mahalanobis and Gaussian gating distances  
+
+**Appearance / ReID** (`include/motcpp/appearance/`, `src/appearance/`)  
+- `ReIDBackend` — abstract interface for feature extraction  
+- `ONNXBackend` — ONNX Runtime implementation  
+- Used by: DeepOC-SORT, StrongSORT, BoT-SORT, BoostTrack, HybridSORT
+
+**Configuration** (`include/motcpp/config.hpp`, `src/config.cpp`)  
+YAML-based config loading. Per-tracker default configs live in `configs/trackers/*.yaml`. Supports float/int/bool/string parameters.
+
+### Tracker Categories
+
+| Motion-only | Appearance (ReID) required |
+|-------------|---------------------------|
+| SORT, ByteTrack, OC-SORT, UCMCTrack, OracleTrack | DeepOC-SORT, StrongSORT, BoT-SORT, BoostTrack, HybridSORT |
+
+### Source Layout
+
+```
+include/motcpp/       ← Public headers (installed with library)
+  motcpp.hpp          ← Single-include entrypoint
+  tracker.hpp         ← BaseTracker interface
+  trackers/           ← One header per tracker
+  motion/             ← Kalman filter interfaces
+  appearance/         ← ReID backend interfaces
+  utils/              ← IoU, matching, ops
+  association/        ← LAP solver
+
+src/                  ← Implementations (.cpp)
+  trackers/ motion/ appearance/ utils/ data/
+
+tests/                ← GoogleTest unit tests (per module)
+configs/trackers/     ← YAML defaults per tracker
+cmake/                ← ONNX download, model export, package config
+scripts/              ← Benchmarking, ReID export, eval helpers
+assets/               ← MOT17 mini datasets for testing
+```
+
+## Code Style
+
+The repo uses `.clang-format`. Run before committing:
+```bash
+clang-format -i src/**/*.cpp include/**/*.hpp
+```
+
+## Adding a New Tracker
+
+1. Add header to `include/motcpp/trackers/my_tracker.hpp` inheriting `BaseTracker`
+2. Add implementation to `src/trackers/my_tracker.cpp`
+3. Include it in `include/motcpp/motcpp.hpp`
+4. Add a YAML config to `configs/trackers/`
+5. Register in `src/tracker_factory.cpp` (if a factory exists) or the CMakeLists source list
+6. Add tests in `tests/test_my_tracker.cpp`