feat: auto-link phrases in the resolve answer (tracer)

- golem15_seo_autolinks (migration 202610280007) and the settings column
  autolink_max (Links tab, 0 to 20, default 3)
- classes/autolinks.go: checked save and delete with history, ForPage
- ok resolve answers carry autolinks for the page's locale without
  disabled phrases and links to the page itself, and autolink_max

classes/resolver.go

@@ -67,6 +67,12 @@ type Result struct {
 	// Outbound is how the layer renders links to other sites (P33-16),
 	// present on ok answers.
 	Outbound *Outbound `json:"outbound,omitempty"`
+	// Autolinks are the auto-link phrases of the page's locale without
+	// those linking to the page itself, longest first, and AutolinkMax the
+	// most the layer links in one text (D-82); present on ok answers, no
+	// phrases when AutolinkMax is 0.
+	Autolinks   []AutolinkLink `json:"autolinks,omitempty"`
+	AutolinkMax *int           `json:"autolink_max,omitempty"`
 	// HTMLLang is the page's <html lang> (P33-21); Alternates its hreflang
 	// list, the page itself and x-default included (D-55 to D-57); JSONLD
 	// its one @graph (D-43); Breadcrumbs its trail, the same items as the
@@ -799,8 +805,15 @@ func (r *Resolver) resolveAt(ctx context.Context, db *gorm.DB, settings models.S
 	res.Action, res.Status, res.Locale, res.SEO = ActionOK, 200, locale, seo
 	res.Outbound = OutboundOf(settings)
 	// The sitemap filter (production) decides on robots and canonical
-	// only; it skips the structured data.
+	// only; it skips the auto-links and the structured data.
 	if !r.production {
+		most := min(models.MaxAutolinkMax, max(models.MinAutolinkMax, settings.AutolinkMax))
+		res.AutolinkMax = &most
+		if most > 0 {
+			if res.Autolinks, err = svc.ForPage(ctx, db, locale, path); err != nil {
+				return Result{}, err
+			}
+		}
 		if err := svc.structuredData(ctx, db, settings, &res, structuredIn{
 			key: key, id: res.RecordID, rec: rec, entry: entry, content: content,
 			locale: locale, path: path, url: self, home: home, siteName: svc.SiteName(ctx, settings, locale), seo: seo,