Add a search box module and a search page

Readers had no way to find a post. The new "search" module goes in the
header (a bar under the nav) or a side column (a box with a heading) and
is a plain GET form to /search, so it works without JavaScript. The
results page lists the published posts of every page whose title or
Markdown body matches the query — case-insensitive, each word literal,
spaces meaning "anything in between", in order — as title, date and a
short snippet with the match marked, 20 per page.

modules.kind is a CHECK constraint, so a migration widens it; "search"
becomes a reserved page slug so the literal route keeps winning over
/{page}. moduleHasSettings now takes the module: a header search box
has no heading, hence nothing to edit.

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

1 files changed, 4 insertions, 2 deletions

diff --git a/internal/web/templates/dashboard/module_form.html b/internal/web/templates/dashboard/module_form.html
index 8b28f2e..a0fe95b 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") (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>
+    {{if or (eq $m.Kind "recent") (eq $m.Kind "archive") (eq $m.Kind "sitemap") (eq $m.Kind "tags") (eq $m.Kind "tagcloud") (eq $m.Kind "search") (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"}}{{else if eq $m.Kind "search"}}{{t "Search"}}{{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>
@@ -20,6 +20,8 @@
     <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 "search"}}
+    <p class="muted small">{{t "A box that searches the published posts of every page by title and text; the results open on your blog’s search page. Case does not matter, and several words find posts that contain them in that order, with anything in between."}}</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>