feat: escalate brain search to web when facts cannot confirm

internal/brain/web.go

@@ -0,0 +1,56 @@
+package brain
+
+import (
+	"context"
+
+	"github.com/eSlider/2dph/internal/brain/rank"
+	"github.com/eSlider/2dph/internal/websearch"
+)
+
+func lookupWeb(ctx context.Context, query string) rank.SecondSource {
+	o := websearch.Lookup(ctx, query, websearch.LookupOpt{Limit: 5})
+	return toSecond(o)
+}
+
+func toSecond(o websearch.Output) rank.SecondSource {
+	hits := make([]rank.SecondSourceHit, 0, len(o.Results))
+	for _, h := range o.Results {
+		hits = append(hits, rank.SecondSourceHit{
+			Rank:    h.Rank,
+			Title:   h.Title,
+			URL:     h.URL,
+			Snippet: h.Snippet,
+			Engine:  h.Engine,
+		})
+	}
+	return rank.SecondSource{
+		Status:  o.Status,
+		Note:    o.Note,
+		Cached:  o.Cached,
+		Results: hits,
+	}
+}
+
+func secondToDict(w rank.SecondSource) Dict {
+	d := Dict{
+		{"status", w.Status},
+	}
+	if w.Note != "" {
+		d = append(d, KV{"note", w.Note})
+	}
+	if w.Cached {
+		d = append(d, KV{"cached", true})
+	}
+	rows := make([]any, 0, len(w.Results))
+	for _, h := range w.Results {
+		rows = append(rows, Dict{
+			{"rank", h.Rank},
+			{"title", h.Title},
+			{"url", h.URL},
+			{"snippet", h.Snippet},
+			{"engine", h.Engine},
+		})
+	}
+	d = append(d, KV{"results", rows})
+	return d
+}