Add CI: GitHub Actions build for Ubuntu and macOS

The TE modules are JUCE INTERFACE libraries — header-only until a
consumer pulls them in — so CI needs an actual link target to compile
the .cpp files. Adds:

- ci/compile_check.cpp: tiny console-app entry that constructs an
  Engine and exits, just to force every module .cpp to be compiled.
- CMakeLists.txt: TE_BUILD_COMPILE_CHECK option (off by default) that
  pulls compile_check.cpp into a juce_add_console_app target and links
  the three TE modules.
- .github/workflows/build.yml: matrix build on ubuntu-latest and
  macos-latest, Release config, runs on push to main/master/feat/**/
  fix/**, on every PR, and on manual dispatch. Per-ref concurrency
  cancellation so superseded runs don't queue.

Forks without CI silently miss compile breakage between MAGDA bumps —
this catches it before merge instead of at the consumer's build.

Author: lucaromagnoli

.github/workflows/build.yml

@@ -0,0 +1,69 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - main
+      - master
+      - "feat/**"
+      - "fix/**"
+  pull_request:
+  workflow_dispatch:
+
+# Cancel in-progress runs when a new commit is pushed to the same ref.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: ${{ matrix.os }} / ${{ matrix.config }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ ubuntu-latest, macos-latest ]
+        config: [ Release ]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Install Linux build dependencies
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            ninja-build \
+            libasound2-dev libjack-jackd2-dev \
+            libcurl4-openssl-dev libfreetype-dev libfontconfig1-dev \
+            libx11-dev libxcomposite-dev libxcursor-dev libxext-dev \
+            libxinerama-dev libxrandr-dev libxrender-dev \
+            libgl1-mesa-dev
+
+      - name: Install macOS build dependencies
+        if: runner.os == 'macOS'
+        run: brew install ninja
+
+      - name: Configure
+        run: >
+          cmake -S . -B build
+          -G Ninja
+          -DCMAKE_BUILD_TYPE=${{ matrix.config }}
+          -DTE_BUILD_COMPILE_CHECK=ON
+
+      - name: Build
+        run: cmake --build build --config ${{ matrix.config }} --parallel
+
+      - name: Upload build log on failure
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: build-log-${{ matrix.os }}-${{ matrix.config }}
+          path: |
+            build/CMakeFiles/CMakeOutput.log
+            build/CMakeFiles/CMakeError.log
+            build/.ninja_log
+          if-no-files-found: ignore

CMakeLists.txt

@@ -3,6 +3,12 @@ cmake_minimum_required(VERSION 3.15)
 # Add a build option for enabling examples (OFF by default for Magica minimal build)
 option(TE_ADD_EXAMPLES "Add the example targets" OFF)
 
+# When ON, builds a tiny console app that links the TE modules so CI actually
+# compiles the .cpp files (the modules themselves are header-only INTERFACE
+# targets until a consumer pulls them in). See ci/compile_check.cpp and
+# .github/workflows/build.yml.
+option(TE_BUILD_COMPILE_CHECK "Build the CI compile-check target" OFF)
+
 # Read version from VERSION.md
 file(READ VERSION.md CURRENT_VERSION)
 string(STRIP ${CURRENT_VERSION} CURRENT_VERSION)
@@ -27,3 +33,26 @@ if (TE_ADD_EXAMPLES)
     enable_testing()
     add_subdirectory(examples)
 endif()
+
+if (TE_BUILD_COMPILE_CHECK)
+    juce_add_console_app(te_compile_check
+        PRODUCT_NAME "te-compile-check")
+
+    target_sources(te_compile_check PRIVATE ci/compile_check.cpp)
+
+    target_compile_definitions(te_compile_check PRIVATE
+        JUCE_USE_CURL=0
+        JUCE_WEB_BROWSER=0
+        JUCE_PLUGINHOST_VST3=0
+        JUCE_PLUGINHOST_AU=0
+        JUCE_PLUGINHOST_LADSPA=0)
+
+    target_link_libraries(te_compile_check PRIVATE
+        tracktion::tracktion_engine
+        tracktion::tracktion_core
+        tracktion::tracktion_graph
+        juce::juce_audio_utils
+        juce::juce_recommended_config_flags
+        juce::juce_recommended_lto_flags
+        juce::juce_recommended_warning_flags)
+endif()

ci/compile_check.cpp

@@ -0,0 +1,16 @@
+// Minimal compile-check consumer for the Tracktion Engine modules.
+// Linked into the te_compile_check console app target when TE_BUILD_COMPILE_CHECK
+// is ON (used by .github/workflows/build.yml). The point is to force every
+// .cpp in tracktion_core / tracktion_engine / tracktion_graph to actually
+// compile under CI — JUCE module libraries are header-only INTERFACE targets
+// until something downstream pulls them in.
+
+#include <tracktion_engine/tracktion_engine.h>
+
+int main()
+{
+    // Construct an Engine just to make sure the module's static init paths
+    // run cleanly. Anything more would be a runtime test, not a build smoke.
+    tracktion::engine::Engine engine { "te-compile-check" };
+    return 0;
+}