Pin Ruby 4.0 in CI and deploy, check links in CI

html-proofer runs after the CI build (internal links only; --no-enforce-https
for one http-only external link).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: cb341

.github/workflows/ci.yml

@@ -12,7 +12,8 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.3"
+          ruby-version: "4.0"
           bundler-cache: true
       - run: bin/check_unicode
       - run: bundle exec jekyll build
+      - run: bundle exec htmlproofer _site --disable-external --no-enforce-https

.github/workflows/deploy.yml

@@ -24,7 +24,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.3"
+          ruby-version: "4.0"
           bundler-cache: true
       - run: bundle exec jekyll build
       - uses: actions/configure-pages@v5

Gemfile

@@ -3,6 +3,7 @@ source "https://rubygems.org"
 gem "jekyll", "~> 4.3"
 gem "htmlbeautifier"
 gem "fastimage"
+gem "html-proofer"
 
 group :jekyll_plugins do
   gem "jekyll-sitemap"

Gemfile.lock

@@ -1,16 +1,32 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    Ascii85 (2.0.1)
     addressable (2.8.8)
       public_suffix (>= 2.0.2, < 8.0)
+    afm (1.0.0)
+    async (2.39.0)
+      console (~> 1.29)
+      fiber-annotation
+      io-event (~> 1.11)
+      metrics (~> 0.12)
+      traces (~> 0.18)
     base64 (0.3.0)
+    benchmark (0.5.0)
     bigdecimal (4.0.1)
     colorator (1.1.0)
     concurrent-ruby (1.3.6)
+    console (1.36.0)
+      fiber-annotation
+      fiber-local (~> 1.1)
+      json
     csv (3.3.5)
     em-websocket (0.5.3)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0)
+    ethon (0.18.0)
+      ffi (>= 1.15.0)
+      logger
     eventmachine (1.2.7)
     fastimage (2.4.0)
     ffi (1.17.3)
@@ -24,6 +40,10 @@ GEM
     ffi (1.17.3-x86_64-darwin)
     ffi (1.17.3-x86_64-linux-gnu)
     ffi (1.17.3-x86_64-linux-musl)
+    fiber-annotation (0.2.0)
+    fiber-local (1.1.0)
+      fiber-storage
+    fiber-storage (1.0.1)
     forwardable-extended (2.6.0)
     google-protobuf (4.33.5)
       bigdecimal
@@ -52,10 +72,22 @@ GEM
     google-protobuf (4.33.5-x86_64-linux-musl)
       bigdecimal
       rake (>= 13)
+    hashery (2.1.2)
+    html-proofer (5.2.1)
+      addressable (~> 2.3)
+      async (~> 2.1)
+      benchmark (~> 0.5)
+      nokogiri (~> 1.13)
+      pdf-reader (~> 2.11)
+      rainbow (~> 3.0)
+      typhoeus (~> 1.3)
+      yell (~> 2.0)
+      zeitwerk (~> 2.5)
     htmlbeautifier (1.4.3)
     http_parser.rb (0.8.1)
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
+    io-event (1.16.1)
     jekyll (4.4.1)
       addressable (~> 2.4)
       base64 (~> 0.2)
@@ -93,15 +125,45 @@ GEM
       rb-inotify (~> 0.9, >= 0.9.10)
     logger (1.7.0)
     mercenary (0.4.0)
+    metrics (0.15.0)
+    mini_portile2 (2.8.9)
+    nokogiri (1.19.3)
+      mini_portile2 (~> 2.8.2)
+      racc (~> 1.4)
+    nokogiri (1.19.3-aarch64-linux-gnu)
+      racc (~> 1.4)
+    nokogiri (1.19.3-aarch64-linux-musl)
+      racc (~> 1.4)
+    nokogiri (1.19.3-arm-linux-gnu)
+      racc (~> 1.4)
+    nokogiri (1.19.3-arm-linux-musl)
+      racc (~> 1.4)
+    nokogiri (1.19.3-arm64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.19.3-x86_64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.19.3-x86_64-linux-gnu)
+      racc (~> 1.4)
+    nokogiri (1.19.3-x86_64-linux-musl)
+      racc (~> 1.4)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
+    pdf-reader (2.15.1)
+      Ascii85 (>= 1.0, < 3.0, != 2.0.0)
+      afm (>= 0.2.1, < 2)
+      hashery (~> 2.0)
+      ruby-rc4
+      ttfunk
     public_suffix (7.0.2)
+    racc (1.8.1)
+    rainbow (3.1.1)
     rake (13.3.1)
     rb-fsevent (0.11.2)
     rb-inotify (0.11.1)
       ffi (~> 1.0)
     rexml (3.4.4)
     rouge (4.7.0)
+    ruby-rc4 (0.1.5)
     safe_yaml (1.0.5)
     sass-embedded (1.97.3)
       google-protobuf (~> 4.31)
@@ -136,8 +198,14 @@ GEM
       google-protobuf (~> 4.31)
     terminal-table (3.0.2)
       unicode-display_width (>= 1.1.1, < 3)
+    traces (0.18.2)
+    ttfunk (1.7.0)
+    typhoeus (1.6.0)
+      ethon (>= 0.18.0)
     unicode-display_width (2.6.0)
     webrick (1.9.2)
+    yell (2.2.2)
+    zeitwerk (2.8.2)
 
 PLATFORMS
   aarch64-linux-android
@@ -162,6 +230,7 @@ PLATFORMS
 
 DEPENDENCIES
   fastimage
+  html-proofer
   htmlbeautifier
   jekyll (~> 4.3)
   jekyll-sitemap