Harden PhantomKit and add release docs

Author: chrisq-dev

.github/workflows/build.yml

@@ -3,9 +3,14 @@ name: Build Firmware
 on:
   push:
     branches: [ main ]
+    tags:
+      - 'v*.*.*'
   pull_request:
     branches: [ main ]
 
+permissions:
+  contents: write
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -32,3 +37,31 @@ jobs:
 
       - name: Compile firmware
         run: pio run
+
+      - name: Build filesystem image
+        run: pio run --target buildfs
+
+      - name: Prepare release assets
+        if: startsWith(github.ref, 'refs/tags/')
+        run: |
+          mkdir -p release
+          cp .pio/build/nodemcuv2/firmware.bin release/phantomkit-${{ github.ref_name }}-firmware.bin
+          cp .pio/build/nodemcuv2/littlefs.bin release/phantomkit-${{ github.ref_name }}-littlefs.bin
+          cd release
+          sha256sum *.bin > SHA256SUMS.txt
+
+      - name: Upload CI artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: phantomkit-firmware
+          path: |
+            .pio/build/nodemcuv2/firmware.bin
+            .pio/build/nodemcuv2/littlefs.bin
+          if-no-files-found: error
+
+      - name: Publish GitHub Release
+        if: startsWith(github.ref, 'refs/tags/')
+        uses: softprops/action-gh-release@v2
+        with:
+          files: release/*
+          generate_release_notes: true

.gitignore

@@ -0,0 +1,8 @@
+.pio/
+.vscode/
+*.bin
+*.elf
+*.map
+*.log
+.DS_Store
+Thumbs.db