chore: harden repository collaboration

.github/dependabot.yml

@@ -0,0 +1,14 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+      day: monday
+      time: "06:00"
+      timezone: Europe/Zurich
+    open-pull-requests-limit: 3
+    groups:
+      github-actions:
+        patterns: ["*"]
+        update-types: [minor, patch]

.github/workflows/ci.yml

@@ -0,0 +1,44 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  quality:
+    name: Quality
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - name: Parse PowerShell scripts
+        shell: pwsh
+        run: |
+          $parseErrors = @()
+          Get-ChildItem -Path . -Recurse -Filter '*.ps1' -File | ForEach-Object {
+            $tokens = $null
+            $errors = $null
+            [void][System.Management.Automation.Language.Parser]::ParseFile(
+              $_.FullName,
+              [ref]$tokens,
+              [ref]$errors
+            )
+            $parseErrors += $errors
+          }
+          if ($parseErrors.Count -gt 0) {
+            $parseErrors | ForEach-Object { Write-Error $_ }
+            exit 1
+          }