docs: update changelog and ci

.github/workflows/ci.yml

@@ -0,0 +1,52 @@
+name: CI
+
+on:
+  push:
+    branches: ["**"]
+  pull_request:
+
+jobs:
+  format:
+    name: Format Check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install clang-format
+        run: sudo apt-get update && sudo apt-get install -y clang-format
+
+      - name: Verify formatting
+        run: |
+          files=$(git ls-files '*.c' '*.cpp' '*.h' '*.hpp')
+          if [ -z "$files" ]; then
+            echo "No C/C++ files to check."
+            exit 0
+          fi
+          clang-format --version
+          clang-format --dry-run --Werror $files
+
+  build:
+    name: PlatformIO Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Cache PlatformIO
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.platformio
+          key: ${{ runner.os }}-platformio-${{ hashFiles('platformio.ini') }}
+
+      - name: Install PlatformIO
+        run: python -m pip install --upgrade platformio
+
+      - name: Build (default env)
+        run: pio run -e tlora_pager_sx1262