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, 5 insertions, 1 deletions

diff --git a/internal/web/handlers_layout.go b/internal/web/handlers_layout.go
index 64d8ff4..d89cd18 100644
--- a/internal/web/handlers_layout.go
+++ b/internal/web/handlers_layout.go
@@ -126,6 +126,10 @@ func (s *Server) handleModuleAdd(w http.ResponseWriter, r *http.Request) {
 		m.Count = 10
 	case "tagcloud":
 		m.Title = i18n.T(blogLang, "Tag cloud")
+	case "search":
+		if area != "header" {
+			m.Title = i18n.T(blogLang, "Search")
+		}
 	}
 	m, err := blogStore(r).CreateModule(r.Context(), m)
 	if err != nil {
@@ -166,7 +170,7 @@ func (s *Server) handleModuleForm(w http.ResponseWriter, r *http.Request) {
 	if m == nil {
 		return
 	}
-	if !moduleHasSettings(m.Kind) {
+	if !moduleHasSettings(*m) {
 		http.Redirect(w, r, s.layoutURL(r), http.StatusSeeOther)
 		return
 	}