follow list fetching test and related changes and fixes.

- make BatchedSubManyEose() use a single duplicate id index and use it for replaceable loaders;
- fixes parsing follow entry from kind:3 events (and others);
- adds a "cause" to most cancelation errors in relay/pool;
- remove the inherent cache from dataloader (we have our own hopefully);
- increase max frame size we can read from any websocket to 2**18 (262k), which gives over 2000 item lists.

sdk/sdk_test.go

@@ -2,13 +2,15 @@ package sdk
 
 import (
 	"context"
+	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/nbd-wtf/go-nostr"
 	"github.com/stretchr/testify/require"
 )
 
-func TestSystemFiatjaf(t *testing.T) {
+func TestMetadataAndEvents(t *testing.T) {
 	sys := NewSystem()
 	ctx := context.Background()
 
@@ -33,3 +35,53 @@ func TestSystemFiatjaf(t *testing.T) {
 	require.NotEmpty(t, events[meta.PubKey])
 	require.GreaterOrEqual(t, len(events[meta.PubKey]), 5)
 }
+
+func TestFollowListRecursion(t *testing.T) {
+	sys := NewSystem()
+	ctx := context.Background()
+
+	// fetch initial follow list
+	followList := sys.FetchFollowList(ctx, "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d")
+	fmt.Println("~", len(followList.Items))
+	require.Greater(t, len(followList.Items), 400, "should follow more than 400 accounts")
+
+	// fetch metadata and follow lists for each followed account concurrently
+	type result struct {
+		pubkey     string
+		followList GenericList[ProfileRef]
+		metadata   ProfileMetadata
+	}
+
+	results := make(chan result)
+	go func() {
+		for _, item := range followList.Items {
+			go func() {
+				fl := sys.FetchFollowList(ctx, item.Pubkey)
+				meta := sys.FetchProfileMetadata(ctx, item.Pubkey)
+				fmt.Println("  ~", item.Pubkey, meta.Name, len(fl.Items))
+				results <- result{item.Pubkey, fl, meta}
+			}()
+		}
+	}()
+
+	// collect results
+	var validAccounts int
+	var accountsWithManyFollows int
+	for i := 0; i < len(followList.Items); i++ {
+		r := <-results
+
+		// skip if metadata has "bot" in name
+		if strings.Contains(strings.ToLower(r.metadata.Name), "bot") {
+			continue
+		}
+
+		validAccounts++
+		if len(r.followList.Items) > 20 {
+			accountsWithManyFollows++
+		}
+	}
+
+	// check if at least 90% of non-bot accounts follow more than 20 accounts
+	ratio := float64(accountsWithManyFollows) / float64(validAccounts)
+	require.Greater(t, ratio, 0.9, "at least 90%% of accounts should follow more than 20 others (actual: %.2f%%)", ratio*100)
+}