Fix build error by moving SD.h/FS.h includes to implementation file

.github/workflows/build-firmware.yml

@@ -0,0 +1,65 @@
+name: Build Skeleton Key Firmware
+
+on:
+  push:
+    branches: [ main, skeleton-key-final ]
+  pull_request:
+    branches: [ main ]
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Cache PlatformIO
+        uses: actions/cache@v3
+        with:
+          path: |
+            ~/.platformio
+            .pio
+          key: ${{ runner.os }}-pio-${{ hashFiles('**/platformio.ini') }}
+          restore-keys: |
+            ${{ runner.os }}-pio-
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install PlatformIO
+        run: |
+          python -m pip install --upgrade pip
+          pip install platformio
+
+      - name: Build Firmware
+        run: |
+          pio run -e m5stack-cardputer
+
+      - name: Upload Firmware Artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: skeleton-key-firmware-${{ github.sha }}
+          path: .pio/build/m5stack-cardputer/firmware.bin
+          retention-days: 30
+
+      - name: Upload Bootloader
+        uses: actions/upload-artifact@v4
+        with:
+          name: skeleton-key-bootloader-${{ github.sha }}
+          path: .pio/build/m5stack-cardputer/bootloader.bin
+          retention-days: 30
+          if-no-files-found: warn
+
+      - name: Upload Partitions
+        uses: actions/upload-artifact@v4
+        with:
+          name: skeleton-key-partitions-${{ github.sha }}
+          path: .pio/build/m5stack-cardputer/partitions.bin
+          retention-days: 30
+          if-no-files-found: warn

drivers/cardputer_adv_driver.h

@@ -1,9 +1,7 @@
 #ifndef CARDPUTER_ADV_DRIVER_H
 #define CARDPUTER_ADV_DRIVER_H
 
-#include <SD.h>
-#include <FS.h>
-
+// Forward declarations - actual includes in .cpp file
 void initialize_driver();
 bool initialize_sd_card();