Add post tags, with a tag page and two side-column modules

Posts can now carry tags, set on the post form as a checklist of the
blog's existing tags plus a comma-separated box for new ones (no JS).
A tag is a name and a unique slug, so "Go" and "go" are one tag and
Greek tags get readable URLs; tags no post uses any more are deleted.

On the blog, tags appear under the post date and link to /tag/<slug>,
which lists the published posts from every page, paginated like a page.
Two new layout modules show them: a Tags list (with counts, by use) and
a Tag cloud (alphabetical, sized by use). Both are only fetched when a
visible module needs them.

The article loop and pager move to a shared postlist partial; while
there, the pager stops adding a trailing slash — /news/?p=2 was a 404
because a {page} wildcard never matches one.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

3 files changed, 13 insertions, 3 deletions

diff --git a/internal/web/templates/dashboard/module_form.html b/internal/web/templates/dashboard/module_form.html
index 0cd27fa..8b28f2e 100644
--- a/internal/web/templates/dashboard/module_form.html
+++ b/internal/web/templates/dashboard/module_form.html
@@ -5,8 +5,8 @@
   <h1>{{.Data.name}} <span class="muted small">{{tf "in the %s" (lower .Data.area)}}</span></h1>
   <form method="post">
     <input type="hidden" name="_csrf" value="{{.CSRF}}">
-    {{if or (eq $m.Kind "recent") (eq $m.Kind "archive") (eq $m.Kind "sitemap") (and (eq $m.Kind "html") (or (eq $m.Area "left") (eq $m.Area "right") (eq $m.Area "footer")))}}
-    <label>{{t "Heading"}} <span class="muted">({{t "optional"}})</span><br><input name="title" value="{{$m.Title}}" maxlength="120" placeholder="{{if eq $m.Kind "recent"}}{{t "Recent posts"}}{{else if eq $m.Kind "archive"}}{{t "Archive"}}{{else if eq $m.Kind "sitemap"}}{{t "Pages"}}{{end}}"></label>
+    {{if or (eq $m.Kind "recent") (eq $m.Kind "archive") (eq $m.Kind "sitemap") (eq $m.Kind "tags") (eq $m.Kind "tagcloud") (and (eq $m.Kind "html") (or (eq $m.Area "left") (eq $m.Area "right") (eq $m.Area "footer")))}}
+    <label>{{t "Heading"}} <span class="muted">({{t "optional"}})</span><br><input name="title" value="{{$m.Title}}" maxlength="120" placeholder="{{if eq $m.Kind "recent"}}{{t "Recent posts"}}{{else if eq $m.Kind "archive"}}{{t "Archive"}}{{else if eq $m.Kind "sitemap"}}{{t "Pages"}}{{else if eq $m.Kind "tags"}}{{t "Tags"}}{{else if eq $m.Kind "tagcloud"}}{{t "Tag cloud"}}{{end}}"></label>
     {{end}}
     {{if eq $m.Kind "recent"}}
     <div class="row"><label>{{t "How many posts"}}<br><select name="count">{{range $n := .Data.counts}}<option value="{{$n}}"{{if eq $n $m.Count}} selected{{end}}>{{$n}}</option>{{end}}</select></label></div>
@@ -15,6 +15,11 @@
     <p class="muted small">{{t "Every published post grouped by year and month, newest first. Years and months fold open and shut; the latest year starts open."}}</p>
     {{else if eq $m.Kind "sitemap"}}
     <p class="muted small">{{t "Links to every page of your blog."}}</p>
+    {{else if eq $m.Kind "tags"}}
+    <div class="row"><label>{{t "How many tags"}}<br><select name="count"><option value="0"{{if eq $m.Count 0}} selected{{end}}>{{t "All"}}</option>{{range $n := .Data.tagCounts}}<option value="{{$n}}"{{if eq $n $m.Count}} selected{{end}}>{{$n}}</option>{{end}}</select></label></div>
+    <p class="muted small">{{t "Your tags with the number of posts in each, most used first. Only published posts count."}}</p>
+    {{else if eq $m.Kind "tagcloud"}}
+    <p class="muted small">{{t "Every tag in alphabetical order, bigger the more posts use it."}}</p>
     {{else if eq $m.Kind "html"}}
     <label for="mod-body">HTML</label>
     <textarea id="mod-body" name="body" rows="14" class="mono" spellcheck="false" placeholder="&lt;p&gt;{{t "Hello!"}}&lt;/p&gt;">{{$m.Body}}</textarea>
diff --git a/internal/web/templates/dashboard/post_form.html b/internal/web/templates/dashboard/post_form.html
index 9f188f7..fd47615 100644
--- a/internal/web/templates/dashboard/post_form.html
+++ b/internal/web/templates/dashboard/post_form.html
@@ -14,6 +14,11 @@
       <label>{{t "Date"}}<br>
         <input type="datetime-local" name="posted_at" value="{{.Data.post.CreatedAt.Format "2006-01-02T15:04"}}" placeholder="YYYY-MM-DD HH:MM"></label>
     </div>
+    {{if .Data.allTags}}<p class="lbl">{{t "Tags"}}</p>
+    <div class="tagpick">{{range .Data.allTags}}<label class="check"><input type="checkbox" name="tag" value="{{.Name}}"{{if index $.Data.tagged .Slug}} checked{{end}}> {{.Name}}</label>{{end}}</div>{{end}}
+    <label>{{if .Data.allTags}}{{t "New tags"}}{{else}}{{t "Tags"}}{{end}} <span class="muted">({{t "comma-separated"}})</span><br>
+      <input name="new_tags" value="{{.Data.newTags}}" maxlength="900" placeholder="{{t "go, tomatoes, recipes"}}"></label>
+    <p class="muted small">{{t "Tags on hidden posts are not shown on the blog; a tag nobody uses disappears."}}</p>
     <label for="ed-body">{{t "Content"}} <span class="muted">(Markdown)</span></label>
     {{template "editor" (dict "name" "body" "value" .Data.post.BodyMD "rows" 24 "tall" true "upload" (print "/b/" .Blog.Subdomain "/files/upload") "preview" (print "/b/" .Blog.Subdomain "/preview") "csrf" .CSRF)}}
     <label class="check"><input type="checkbox" name="published"{{if .Data.post.Published}} checked{{end}}> {{t "Visible on the blog"}}</label>
diff --git a/internal/web/templates/dashboard/posts.html b/internal/web/templates/dashboard/posts.html
index 3a99a31..983fbae 100644
--- a/internal/web/templates/dashboard/posts.html
+++ b/internal/web/templates/dashboard/posts.html
@@ -17,7 +17,7 @@
 <table>
   <tr><th>{{t "Title"}}</th><th>{{t "Page"}}</th><th>{{t "Date"}}</th><th></th></tr>
   {{range .Data.posts}}<tr>
-    <td><a href="/b/{{$.Blog.Subdomain}}/posts/{{.ID}}/edit">{{.Title}}</a>{{if not .Published}} <span class="tag">{{t "hidden"}}</span>{{end}}</td>
+    <td><a href="/b/{{$.Blog.Subdomain}}/posts/{{.ID}}/edit">{{.Title}}</a>{{if not .Published}} <span class="tag">{{t "hidden"}}</span>{{end}}{{if .Tags}}<div class="muted small">{{range $i, $t := .Tags}}{{if $i}}, {{end}}{{$t.Name}}{{end}}</div>{{end}}</td>
     <td>{{.PageTitle}}</td>
     <td class="nowrap">{{date .CreatedAt}}</td>
     <td class="nowrap"><a href="{{$.BlogURL}}/{{.PageSlug}}/{{.Slug}}" target="_blank">{{t "view"}} &#8599;</a> &middot; <a class="danger" href="/b/{{$.Blog.Subdomain}}/posts/{{.ID}}/delete">{{t "delete"}}</a></td>