[Feat] (trace-replay): add Linux retrace CI

tools/trace_replay/README.md

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+# MobileGL trace replay
+
+This directory builds a Linux command line replay runner for apitrace files. It is meant for CI coverage of MobileGL
+without Android, APK packaging, FCL, or plugin runtime dependencies.
+
+Build from the MobileGL repository root:
+
+```sh
+cmake -S . -B build-test -G Ninja \
+  -DMOBILEGL_BUILD_TEST=ON \
+  -DMOBILEGL_BUILD_BENCHMARK=OFF \
+  -DMOBILEGL_BUILD_TRACE_REPLAY=ON
+cmake --build build-test
+```
+
+Run the OpenRA fixture test:
+
+```sh
+ctest --test-dir build-test -V -R MobileGLTraceReplay.OpenRA.DirectGLES
+```
+
+Run the CLI directly:
+
+```sh
+build-test/tools/trace_replay/mobilegl_trace_replay \
+  --trace openra.trace \
+  --golden openra.0000031249.png \
+  --output out/openra \
+  --backend DirectGLES \
+  --mobilegl-library build-test/libMobileGL.so \
+  --target-call 31249 \
+  --width 640 \
+  --height 480 \
+  --crop-x 1 \
+  --crop-y 1 \
+  --crop-width 638 \
+  --crop-height 478 \
+  --tolerance 20 \
+  --fuzz-percent 20
+```
+
+The Linux runner uses an EGL pbuffer shim and loads MobileGL by path with `dlopen`. The current CI test covers the
+OpenRA core-profile trace through the `DirectGLES` backend. `DirectVulkan` is still available as a CLI argument, but it
+requires a native window/swapchain path and is not part of the headless CI test yet.