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, 3 deletions

diff --git a/internal/web/web_test.go b/internal/web/web_test.go
index afb289a..b803003 100644
--- a/internal/web/web_test.go
+++ b/internal/web/web_test.go
@@ -74,7 +74,7 @@ func TestRootRoutePrecedence(t *testing.T) {
 			t.Errorf("%s: got %d, want %d", path, rec.Code, want)
 		}
 	}
-	for _, slug := range []string{"webadmin", "admin", "b", "media", "feed.xml", "favicon.ico", "tag"} {
+	for _, slug := range []string{"webadmin", "admin", "b", "media", "feed.xml", "favicon.ico", "tag", "search"} {
 		if !reservedPageSlugs[slug] {
 			t.Errorf("page slug %q should be reserved", slug)
 		}
@@ -192,7 +192,8 @@ func TestModuleKinds(t *testing.T) {
 	if !allowedKind("header", "menu") || allowedKind("header", "archive") || allowedKind("above", "menu") || allowedKind("attic", "html") {
 		t.Error("allowedKind")
 	}
-	if !moduleHasSettings("html") || moduleHasSettings("rss") {
+	if !moduleHasSettings(store.Module{Kind: "html"}) || moduleHasSettings(store.Module{Kind: "rss"}) ||
+		!moduleHasSettings(store.Module{Kind: "search", Area: "left"}) || moduleHasSettings(store.Module{Kind: "search", Area: "header"}) {
 		t.Error("moduleHasSettings")
 	}
 	if got := moduleSummary("en", store.Module{Kind: "recent", Count: 5, Title: "Fresh"}); got != "5 posts, heading “Fresh”" {
@@ -379,7 +380,7 @@ func TestAllTemplatesParse(t *testing.T) {
 	for _, name := range []string{"auth/login.html", "dashboard/overview.html", "dashboard/pages.html", "dashboard/page_form.html",
 		"dashboard/posts.html", "dashboard/post_form.html", "dashboard/design.html", "dashboard/files.html", "dashboard/settings.html",
 		"dashboard/password.html", "dashboard/confirm.html", "dashboard/sections.html", "dashboard/section_form.html", "dashboard/layout.html", "dashboard/module_form.html", "admin/index.html", "admin/new_user.html", "admin/delete_user.html",
-		"blog/page.html", "blog/post.html", "blog/tag.html", "blog/404.html"} {
+		"blog/page.html", "blog/post.html", "blog/tag.html", "blog/search.html", "blog/404.html"} {
 		for _, l := range i18n.Languages() {
 			if _, err := tpl.get(l.Code, name); err != nil {
 				t.Errorf("%s (%s): %v", name, l.Code, err)