github: Add clang format check workflow.

Signed-off-by: iabdalkader <[email protected]>

Author: iabdalkader

.github/workflows/format_check.yml

@@ -0,0 +1,69 @@
+name: 'Format Check'
+
+on:
+  push:
+    branches:
+      - 'main'
+    paths:
+      - '**/*.{c,cpp,cc,cxx,h,hpp}'
+
+  pull_request:
+    types:
+      - opened
+      - edited
+      - reopened
+      - synchronize
+    branches:
+      - 'main'
+    paths:
+      - '**/*.{c,cpp,cc,cxx,h,hpp}'
+
+  workflow_dispatch:
+    inputs:
+      logLevel:
+        description: 'Log level'     
+        required: true
+        default: 'warning'
+
+jobs:
+  format-check:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          submodules: false
+          persist-credentials: false
+
+      - name: Install clang-format
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang-format
+
+      - name: Get changed files
+        id: changed-files
+        uses: tj-actions/changed-files@v46
+        with:
+          files: |
+            cores/arduino/**/*.{c,cpp,cc,cxx,h,hpp}
+            !cores/arduino/api/**
+            loader/**/*.{c,cpp,cc,cxx,h,hpp}
+            !loader/llext_exports.c
+            libraries/**/*.{c,cpp,cc,cxx,h,hpp}
+
+      - name: Run clang-format check
+        if: steps.changed-files.outputs.any_changed == 'true'
+        run: |
+          exit_code=0
+
+          for file in ${{ steps.changed-files.outputs.all_changed_files }}; do
+            file_fmt="${file}.tmp"
+            clang-format ${file} > ${file_fmt}
+            diff -q -u ${file} ${file_fmt} >> /dev/null 2>&1 || {
+              echo "❌ Formatting issues found in: $file"
+              colordiff -u ${file} ${file_fmt} || true
+              exit_code=1
+            }
+          done
+
+          exit $exit_code