Add site search, refresh docs, add preview build workflow

.github/workflows/preview-build.yml

@@ -0,0 +1,52 @@
+name: Preview build
+
+# Builds the site on every push to a non-master branch and uploads the rendered
+# _site/ folder as a downloadable artifact you can preview locally. The live
+# canlab.github.io site (served from master) is not affected.
+
+on:
+  push:
+    branches-ignore:
+      - master
+      - main
+  workflow_dispatch: # also allows running manually from the Actions tab
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out branch
+        uses: actions/checkout@v4
+
+      # The committed Gemfile.lock is from 2018 and pins gems that don't resolve
+      # on modern Ruby. For previews we re-resolve from the Gemfile.
+      - name: Refresh Gemfile.lock
+        run: rm -f Gemfile.lock
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.1"
+          bundler-cache: true
+
+      - name: Build site with Jekyll
+        # Stack _config.preview.yml on top of _config.yml so generated links
+        # are root-relative (work when served from a local http server).
+        run: bundle exec jekyll build --trace --config _config.yml,_config.preview.yml
+        env:
+          JEKYLL_ENV: production
+          # github-pages gem needs the owner/repo when not running inside the
+          # official GitHub Pages builder.
+          PAGES_REPO_NWO: ${{ github.repository }}
+
+      # Future improvement: add an internal-link checker step here (e.g.
+      # lycheeverse/lychee-action) once the existing site is clean enough
+      # not to fail every build. Run locally with htmlproofer first to
+      # establish a baseline.
+
+      - name: Upload built site as artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: site-${{ github.ref_name }}-${{ github.sha }}
+          path: _site
+          retention-days: 14

_config.preview.yml

@@ -0,0 +1,9 @@
+# Overrides used only by the preview build workflow.
+# Empty url + baseurl makes all generated links root-relative so the site
+# works when served from any local web server (e.g. python3 -m http.server).
+
+url: ""
+baseurl: ""
+
+analytics:
+  provider: false

_config.yml

@@ -70,10 +70,17 @@ social:
 
 
 # Analytics
+# Set provider to "google-universal" or "google" and add a tracking_id below to enable.
+# Currently disabled because no tracking ID has been configured (the previous setting
+# loaded the analytics include with no ID, which silently did nothing).
 analytics:
-  provider               :  "google-universal" # false (default), "google", "google-universal", "custom"
+  provider               : false # false (default), "google", "google-universal", "custom"
   google:
-    tracking_id          :
+    tracking_id          : # e.g. "UA-XXXXXXXX-X" or "G-XXXXXXXXXX"
+
+# SEO: to surface this site in search engines, also submit the sitemap (auto-generated
+# at /sitemap.xml by jekyll-sitemap) to Google Search Console at
+# https://search.google.com/search-console — and add the verification token below.
 
 
 # Site Author

_data/navigation.yml

@@ -15,6 +15,9 @@ main:
   - title: "Batch system"
     url: /batch/
 
+  - title: '<i class="fa fa-search" aria-hidden="true"></i> Search'
+    url: /search/
+
   # - title: "Portfolio"
   #  url: /portfolio/