Show the prefix page's origin names from the prefix query (closes #67)

The prefix page looked up each origin AS's details only for its handle and
description, and that lookup also reads every live route the AS originates.
GetPrefixDetailsContext already selects the handle and description; it now
returns them keyed by AS number, and the page uses them instead.

The origin list was handed each description but never rendered it; it now
shows it after the handle.

Model: opus-5-5

internal/server/handlers_test.go

@@ -3,10 +3,13 @@ package server
 import (
 	"context"
 	"encoding/json"
+	"errors"
+	"html"
 	"net/http"
 	"net/http/httptest"
 	"runtime"
 	"slices"
+	"strings"
 	"testing"
 	"time"
 
@@ -15,6 +18,7 @@ import (
 	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
 	"git.eeqj.de/sneak/routewatch/internal/streamer"
+	"git.eeqj.de/sneak/routewatch/pkg/asinfo"
 	"github.com/google/uuid"
 )
 
@@ -200,6 +204,72 @@ func TestPrefixDetailHandlersParsePrefix(t *testing.T) {
 	}
 }
 
+// failingASDetailsDB wraps a real store and fails every AS details lookup.
+type failingASDetailsDB struct {
+	database.Store
+}
+
+func (failingASDetailsDB) GetASDetailsContext(_ context.Context, _ int) (*database.ASN, []database.LiveRoute, error) {
+	return nil, nil, errors.New("AS details lookup failed")
+}
+
+// TestPrefixDetailShowsOriginNames checks that the prefix page shows each
+// origin AS's handle and description without looking up the AS's details,
+// which also read every route the AS originates. Before the fix the page did
+// that lookup once per origin, so with it failing the names were missing
+// (https://git.eeqj.de/sneak/routewatch/issues/67). The AS path column shows
+// handles too, so the test looks for the origin list's "(handle)" form.
+func TestPrefixDetailShowsOriginNames(t *testing.T) {
+	db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("database.New: %v", err)
+	}
+	t.Cleanup(func() { _ = db.Close() })
+
+	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	origins := []int{15169, 13335}
+	for _, asn := range origins {
+		if _, err := db.GetOrCreateASN(asn, ts); err != nil {
+			t.Fatalf("GetOrCreateASN(%d): %v", asn, err)
+		}
+	}
+	if err := db.UpsertLiveRouteBatch([]*database.LiveRoute{
+		{
+			ID: uuid.New(), Prefix: "192.0.2.0/24", MaskLength: 24, IPVersion: 4,
+			OriginASN: origins[0], PeerIP: "198.51.100.1", ASPath: []int{origins[0]}, NextHop: "198.51.100.1",
+			LastUpdated: ts,
+		},
+		{
+			ID: uuid.New(), Prefix: "192.0.2.0/24", MaskLength: 24, IPVersion: 4,
+			OriginASN: origins[1], PeerIP: "198.51.100.2", ASPath: []int{origins[1]}, NextHop: "198.51.100.2",
+			LastUpdated: ts,
+		},
+	}); err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	s := New(failingASDetailsDB{db}, streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+	rec := httptest.NewRecorder()
+	s.router.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/prefix/192.0.2.0/24", nil))
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status %d, want %d; body %s", rec.Code, http.StatusOK, rec.Body)
+	}
+
+	page := rec.Body.String()
+	for _, asn := range origins {
+		info, ok := asinfo.Get(asn)
+		if !ok {
+			t.Fatalf("AS%d is not in the AS info data", asn)
+		}
+		if want := "(" + html.EscapeString(info.Handle) + ")"; !strings.Contains(page, want) {
+			t.Errorf("page does not show AS%d's handle %q", asn, want)
+		}
+		if want := html.EscapeString(info.Description); !strings.Contains(page, want) {
+			t.Errorf("page does not show AS%d's description %q", asn, want)
+		}
+	}
+}
+
 // settledGoroutineCount lets transient goroutines finish, then reports the
 // current count.
 func settledGoroutineCount() int {