Add code coverage job with Codecov upload and workflow_dispatch trigger

- Add workflow_dispatch trigger to enable manual runs via `gh workflow run`
- Add separate `coverage` job that builds in Debug mode with `--coverage` flags
- Use lcov to collect and filter coverage data (excludes 3rdparty, tests, examples)
- Upload coverage.info to Codecov using CODECOV_TOKEN secret
- Keep existing Release build job unchanged

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: facontidavide

.github/workflows/cmake_ubuntu.yml

@@ -6,17 +6,13 @@ on:
       - master
   pull_request:
     types: [opened, synchronize, reopened]
+  workflow_dispatch:
 
 env:
-  # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
   BUILD_TYPE: Release
 
 jobs:
   build:
-    # The CMake configure and build commands are platform agnostic and should work equally
-    # well on Windows or Mac.  You can convert this to a matrix build if you need
-    # cross-platform coverage.
-    # See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
@@ -37,8 +33,6 @@ jobs:
 
     - name: Normalize build type
       shell: bash
-      # The build type is Capitalized, e.g. Release, but the preset is all lowercase, e.g. release.
-      # There is no built in way to do string manipulations on GHA as far as I know.`
       run: echo "BUILD_TYPE_LOWERCASE=$(echo "${BUILD_TYPE}" | tr '[:upper:]' '[:lower:]')" >> $GITHUB_ENV
 
     - name: Configure CMake
@@ -52,5 +46,57 @@ jobs:
     - name: run test (Linux)
       run: ctest --test-dir build/${{env.BUILD_TYPE}}
 
+  coverage:
+    runs-on: ubuntu-22.04
+
+    steps:
+    - uses: actions/checkout@v6
+
+    - name: Install lcov
+      run: sudo apt-get update && sudo apt-get install -y lcov
+
+    - name: Install Conan
+      id: conan
+      uses: turtlebrowser/get-conan@main
+
+    - name: Create default profile
+      run: conan profile detect
+
+    - name: Install conan dependencies
+      run: conan install conanfile.py -s build_type=Debug --build=missing
+
+    - name: Configure CMake with coverage
+      shell: bash
+      run: |
+        cmake --preset conan-debug \
+          -DCMAKE_C_FLAGS="--coverage" \
+          -DCMAKE_CXX_FLAGS="--coverage"
+
+    - name: Build
+      shell: bash
+      run: cmake --build --preset conan-debug
+
+    - name: Run tests
+      run: ctest --test-dir build/Debug --output-on-failure
+
+    - name: Collect coverage
+      run: |
+        lcov --capture --directory build/Debug \
+             --output-file coverage.info \
+             --ignore-errors mismatch
+        lcov --remove coverage.info \
+             '/usr/*' \
+             '*/3rdparty/*' \
+             '*/tests/*' \
+             '*/examples/*' \
+             '*/sample_nodes/*' \
+             '*/tools/*' \
+             --output-file coverage.info \
+             --ignore-errors unused
+        lcov --list coverage.info
+
     - name: Upload coverage reports to Codecov
       uses: codecov/codecov-action@v5
+      with:
+        files: coverage.info
+        token: ${{ secrets.CODECOV_TOKEN }}