Add post changelogs

This replaces the manual `updated_date` field with a changelog flow
field so post updates can be recorded as dated entries.

The blog template now derives the "Last updated" metadata from the
latest changelog entry and renders the full changelog in the article
footer, with dedicated styling for compact change notes.

7 files changed, 99 insertions, 27 deletions

diff --git a/assets/static/css/style.css b/assets/static/css/style.css
index 00e9ee3..dd1ed80 100644
--- a/assets/static/css/style.css
+++ b/assets/static/css/style.css
@@ -684,6 +684,36 @@ article {
     li:not(:first-child) {
       white-space: nowrap;
     }
+
+    .changelog {
+      margin-top: 1.5rem;
+      font-size: 0.85rem;
+
+      & > h3 {
+        font-size: clamp(1.2rem, 2vw, 1.5rem);
+        margin: 0 0 0.75rem;
+      }
+
+      & > ul {
+        margin: 0;
+        padding: 0;
+        list-style: none;
+
+        & > li {
+          display: grid;
+          grid-template-columns: max-content 1fr;
+          gap: 1rem;
+
+          & + li {
+            margin-top: 0.4rem;
+          }
+
+          & > time {
+            color: var(--dim-blue);
+          }
+        }
+      }
+    }
   }
 
   /* --- Article separator --- */
diff --git a/content/blog/hiking-log-1-circuit-korspronk/contents.lr b/content/blog/hiking-log-1-circuit-korspronk/contents.lr
index 7d0a08c..f495c89 100644
--- a/content/blog/hiking-log-1-circuit-korspronk/contents.lr
+++ b/content/blog/hiking-log-1-circuit-korspronk/contents.lr
@@ -58,7 +58,7 @@ The only disadvantage is that I cannot filter them by length or difficulty.
 This prompted me to do some more research, which led me to [Wanderweeër
 Lëtzebuerg (WWL)](https://wwl.lu/index.php/en/wwl-homepage), an independent
 project run by a Luxembourgish hiking enthusiast.
-[Here](https://wwl.lu/index.php/en/dynamic-search), we can filter trails by
+[Here](https://wwl.lu/index.php/en/hiking-trails), we can filter trails by
 keyword, category, distance and difficulty. I looked around to find an easy,
 short local hike and found the *"Circuit Korspronk"*.
 #### trail ####
@@ -185,4 +185,10 @@ several others, which I will document in the future. I already feel that hiking
 helps me to switch off for a few moments by simply taking in the fresh air and
 paying attention to the beautiful, intricate, and sometimes mysterious natural world
 around me.
+---
+changelog:
 
+#### changelog ####
+date: 2026-08-17
+----
+description: Fixed the link to the Wanderweeër Lëtzebuerg search page.
diff --git a/flowblocks/changelog.ini b/flowblocks/changelog.ini
new file mode 100644
index 0000000..3883ca4
--- /dev/null
+++ b/flowblocks/changelog.ini
@@ -0,0 +1,14 @@
+[block]
+name = Changelog entry
+button_label = Add changelog entry
+
+[fields.date]
+label = Date
+type = date
+width = 1/3
+required = true
+
+[fields.description]
+label = Description
+type = string
+width = 2/3
diff --git a/models/blog-post.ini b/models/blog-post.ini
index 006376b..4a91868 100644
--- a/models/blog-post.ini
+++ b/models/blog-post.ini
@@ -10,12 +10,7 @@ size = large
 [fields.publication_date]
 label = Publication date
 type = date
-width = 1/2
-
-[fields.updated_date]
-label = Updated date
-type = date
-width = 1/2
+width = 1
 
 [fields.category]
 label = Category
@@ -46,3 +41,9 @@ label = Body
 type = flow
 flow_blocks = markdown, trail, gallery
 description = Build the post from Markdown sections, trail maps or galleries.
+
+[fields.changelog]
+label = Changelog
+type = flow
+flow_blocks = changelog
+description = Record changes made to the post after publication.
diff --git a/templates/blocks/changelog.html b/templates/blocks/changelog.html
new file mode 100644
index 0000000..eee2bf1
--- /dev/null
+++ b/templates/blocks/changelog.html
@@ -0,0 +1 @@
+{# Changelog entries are rendered by the blog post template. #}
diff --git a/templates/blog-post.html b/templates/blog-post.html
index fe751ae..a8eaf37 100644
--- a/templates/blog-post.html
+++ b/templates/blog-post.html
@@ -13,6 +13,7 @@
 {% endfor %}
 
 {% set needs_trail_assets = features.trail %}
+{% set latest_change = this.changelog.blocks | max(attribute="date") if this.changelog else none %}
 
 {% block meta %}
   {{ super() }}
@@ -22,9 +23,9 @@
     <meta property="article:published_time"
           content="{{ this.publication_date }}T00:00:00+02:00">
   {% endif %}
-  {% if this.updated_date %}
+  {% if latest_change %}
     <meta property="article:modified_time"
-          content="{{ this.updated_date }}T00:00:00+02:00">
+          content="{{ latest_change.date }}T00:00:00+02:00">
   {% endif %}
   {% if this.category %}
     {% set category = site.get("/categories/" + this.category) %}
@@ -46,8 +47,8 @@
     {% set blog_url = '/blog' | url(absolute=True, external=True) %}
     {% set blog_id = blog_url ~ '#blog' %}
     {% set modified_date = this.publication_date %}
-    {% if this.updated_date %}
-      {% set modified_date = this.updated_date %}
+    {% if latest_change %}
+      {% set modified_date = latest_change.date %}
     {% endif %}
     {% set post_description = bag('blog.tagline') %}
     {% if this.description %}
diff --git a/templates/macros/blog.html b/templates/macros/blog.html
index 13c2526..d076762 100644
--- a/templates/macros/blog.html
+++ b/templates/macros/blog.html
@@ -29,6 +29,8 @@
     {% endfor %}
   {% endif %}
 
+  {% set latest_change = post.changelog.blocks | max(attribute="date") if post.changelog else none %}
+
   <article class="h-entry">
     <header>
       <div>
@@ -54,12 +56,12 @@
               </dd>
             </div>
           {% endif %}
-          {% if post.updated_date and post.publication_date and (post.updated_date > post.publication_date) %}
+          {% if latest_change and post.publication_date and latest_change.date > post.publication_date %}
             <div>
               <dt>Last updated:</dt>
               <dd>
-                <time datetime="{{ post.updated_date | dateformat('yyyy-MM-dd') }}"
-                      class="dt-updated">{{ post.updated_date | dateformat("d MMMM yyyy") }}</time>
+                <time datetime="{{ latest_change.date | dateformat('yyyy-MM-dd') }}"
+                      class="dt-updated">{{ latest_change.date | dateformat("d MMMM yyyy") }}</time>
               </dd>
             </div>
           {% endif %}
@@ -82,20 +84,37 @@
       {% endif %}
     </header>
     <div class="e-content">{{ post.body }}</div>
-    {% if post.tags %}
+    {% if post.tags or post.changelog %}
       <footer>
-        <ul aria-label="Tags">
-          <li>Tagged with</li>
-          {% for tag in post.tags %}
-            <li>
-              {% set tag_slug = tag|trim|lower|replace(" ", "-") %}
-              <a href="{{ ('/blog/tag/' ~ tag_slug ~ '/')|url }}"
-                 rel="tag"
-                 class="p-category">{{ tag }}</a>
-              {%- if not loop.last -%}, {%- else -%}.{%- endif -%}
-            </li>
-          {% endfor %}
-        </ul>
+        {% if post.tags %}
+          <ul aria-label="Tags">
+            <li>Tagged with</li>
+            {% for tag in post.tags %}
+              <li>
+                {% set tag_slug = tag|trim|lower|replace(" ", "-") %}
+                <a href="{{ ('/blog/tag/' ~ tag_slug ~ '/')|url }}"
+                   rel="tag"
+                   class="p-category">{{ tag }}</a>
+                {%- if not loop.last -%}, {%- else -%}.{%- endif -%}
+              </li>
+            {% endfor %}
+          </ul>
+        {% endif %}
+        {% if post.changelog %}
+          <section class="changelog" aria-labelledby="changelog-heading">
+            <h3 id="changelog-heading">Changelog</h3>
+            <ul>
+              {% for entry in post.changelog.blocks %}
+                <li>
+                  <time datetime="{{ entry.date | dateformat('yyyy-MM-dd') }}">
+                    {{ entry.date | dateformat("d MMMM yyyy") }}
+                  </time>
+                  <span>{{ entry.description }}</span>
+                </li>
+              {% endfor %}
+            </ul>
+          </section>
+        {% endif %}
       </footer>
     {% endif %}
   </article>