feat: Add devbox configuration and lock files; clean up YAML files by removing trailing newlines

I've fixed the Helm lint errors in the iperf3-monitor chart.

.github/workflows/ci.yaml

@@ -0,0 +1,57 @@
+name: CI
+
+on:
+  pull_request:
+    branches: ["main"] # Or your main development branch
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  validate-chart:
+    name: Validate Helm Chart
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      - name: Set up Helm
+        uses: azure/setup-helm@v3
+        with:
+          version: v3.10.0
+
+      - name: Helm Lint
+        run: helm lint ./charts/iperf3-monitor
+
+  build:
+    name: Build Docker Image
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v4
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build Docker image
+        uses: docker/build-push-action@v4
+        with:
+          context: ./exporter
+          push: false # Do not push on PRs
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+  test:
+    name: Run Tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      # Replace this step with your actual test command(s)
+      - name: Placeholder Test Step
+        run: echo "No tests configured yet. Add your test commands here."

devbox.json

@@ -0,0 +1,14 @@
+{
+  "$schema":  "https://raw.githubusercontent.com/jetify-com/devbox/0.13.7/.schema/devbox.schema.json",
+  "packages": [],
+  "shell": {
+    "init_hook": [
+      "echo 'Welcome to devbox!' > /dev/null"
+    ],
+    "scripts": {
+      "test": [
+        "echo \"Error: no test specified\" && exit 1"
+      ]
+    }
+  }
+}

devbox.lock

@@ -0,0 +1,4 @@
+{
+  "lockfile_version": "1",
+  "packages": {}
+}