feat: enhance observability with prefix aggregation metrics

- Added new histograms to track prefix aggregation duration, raw count, and aggregated count during tenant rendering.
- Implemented `RecordPrefixAggregation` function to record metrics for aggregation performance.
- Updated `RenderTenantRevision` and `RenderTenantRevisionFromPrefixes` functions to log aggregation statistics.
- Refactored `smartAggregatePrefixRows` to support both IPv4 and IPv6 aggregation, improving overall prefix handling.

internal/pipeline/refresh_aggregate_test.go

@@ -8,6 +8,15 @@ import (
 	"evobgp/internal/store"
 )
 
+func prefixRowSet(rows []store.PrefixRow) map[string]struct{} {
+	got := make(map[string]struct{}, len(rows))
+	for _, r := range rows {
+		c := prefixRowCommunity(r)
+		got[r.Prefix+"|"+c+"|"+r.Source] = struct{}{}
+	}
+	return got
+}
+
 func TestRefreshModule_AggregatesAllEnabledModules(t *testing.T) {
 	t.Setenv("EVOBGP_ASN_RESOLVE", "0")
 
@@ -119,3 +128,144 @@ func TestSmartAggregatePrefixRows_RespectsCommunityAndSource(t *testing.T) {
 		t.Fatalf("expected 3 resulting rows, got %d: %+v", len(out), out)
 	}
 }
+
+func TestSmartAggregatePrefixRows_PruneCoveredPrefixes(t *testing.T) {
+	rows := []store.PrefixRow{
+		{Prefix: "10.0.0.0/16", Source: "ip_range"},
+		{Prefix: "10.0.0.0/24", Source: "ip_range"},
+		{Prefix: "10.0.1.0/24", Source: "ip_range"},
+	}
+	out := smartAggregatePrefixRows(rows)
+	got := prefixRowSet(out)
+	if len(out) != 1 {
+		t.Fatalf("expected 1 row after covered prune, got %d: %+v", len(out), out)
+	}
+	if _, ok := got["10.0.0.0/16||ip_range"]; !ok {
+		t.Fatalf("expected /16 only, got: %+v", out)
+	}
+}
+
+func TestSmartAggregatePrefixRows_MergeChainFourSlash24(t *testing.T) {
+	rows := []store.PrefixRow{
+		{Prefix: "10.0.0.0/24", Source: "ip_range"},
+		{Prefix: "10.0.1.0/24", Source: "ip_range"},
+		{Prefix: "10.0.2.0/24", Source: "ip_range"},
+		{Prefix: "10.0.3.0/24", Source: "ip_range"},
+	}
+	out := smartAggregatePrefixRows(rows)
+	got := prefixRowSet(out)
+	if _, ok := got["10.0.0.0/22||ip_range"]; !ok {
+		t.Fatalf("expected merged /22, got: %+v", out)
+	}
+	if len(out) != 1 {
+		t.Fatalf("expected 1 row, got %d: %+v", len(out), out)
+	}
+}
+
+func TestSmartAggregatePrefixRows_DoesNotMergeAdjacentSlash8(t *testing.T) {
+	rows := []store.PrefixRow{
+		{Prefix: "10.0.0.0/8", Source: "ip_range"},
+		{Prefix: "11.0.0.0/8", Source: "ip_range"},
+	}
+	out := smartAggregatePrefixRows(rows)
+	if len(out) != 2 {
+		t.Fatalf("expected two /8 prefixes, got %d: %+v", len(out), out)
+	}
+}
+
+func TestSmartAggregatePrefixRows_MergesIPv6Slash64(t *testing.T) {
+	rows := []store.PrefixRow{
+		{Prefix: "2001:db8:0:0::/64", Source: "ip_range"},
+		{Prefix: "2001:db8:0:1::/64", Source: "ip_range"},
+	}
+	out := smartAggregatePrefixRows(rows)
+	got := prefixRowSet(out)
+	if _, ok := got["2001:db8::/63||ip_range"]; !ok {
+		t.Fatalf("expected merged IPv6 /63, got: %+v", out)
+	}
+	if len(out) != 1 {
+		t.Fatalf("expected 1 row, got %d: %+v", len(out), out)
+	}
+}
+
+func TestSmartAggregatePrefixRows_StableOutputOrder(t *testing.T) {
+	rows := []store.PrefixRow{
+		{Prefix: "192.168.0.0/24", Source: "cdn:b"},
+		{Prefix: "10.0.0.0/24", Source: "ip_range"},
+		{Prefix: "10.0.1.0/24", Source: "ip_range"},
+	}
+	out1 := smartAggregatePrefixRows(rows)
+	out2 := smartAggregatePrefixRows(rows)
+	if len(out1) != len(out2) {
+		t.Fatalf("length mismatch: %d vs %d", len(out1), len(out2))
+	}
+	for i := range out1 {
+		if out1[i].Prefix != out2[i].Prefix || out1[i].Source != out2[i].Source {
+			t.Fatalf("order not stable at %d: %+v vs %+v", i, out1[i], out2[i])
+		}
+	}
+}
+
+func TestRenderTenantRevisionFromPrefixes_SkipsWhenRedundantRawRows(t *testing.T) {
+	t.Setenv("EVOBGP_ASN_RESOLVE", "0")
+
+	m := store.NewMemory()
+	m.SeedDemo()
+	tenant, _, modIP, _, _ := m.DemoIDs()
+	for _, mod := range m.ListModules(tenant) {
+		if mod == nil || mod.ID == modIP {
+			continue
+		}
+		disabled := false
+		if _, err := m.UpdateModule(tenant, mod.ID, &store.ModulePatch{Enabled: &disabled}); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	ctx := context.Background()
+	baseRows := []store.PrefixRow{{Prefix: "10.0.0.0/16", Source: "ip_range"}}
+	rev1, err := RenderTenantRevisionFromPrefixes(ctx, m, http.DefaultClient, tenant, modIP, baseRows)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	rev2, err := RenderTenantRevisionFromPrefixes(ctx, m, http.DefaultClient, tenant, modIP, append(baseRows,
+		store.PrefixRow{Prefix: "10.0.0.0/24", Source: "ip_range"},
+	))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rev2 != rev1 {
+		t.Fatalf("expected hash skip for redundant covered prefix, got rev1=%s rev2=%s", rev1, rev2)
+	}
+
+	before, _, _ := m.ListRevisions(tenant, "", "", 200)
+	rev3, err := RenderTenantRevisionFromPrefixes(ctx, m, http.DefaultClient, tenant, modIP, append(baseRows,
+		store.PrefixRow{Prefix: "10.0.0.0/24", Source: "ip_range"},
+		store.PrefixRow{Prefix: "10.0.0.0/24", Source: "ip_range"},
+	))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rev3 != rev1 {
+		t.Fatalf("expected hash skip for duplicate raw rows, got rev1=%s rev3=%s", rev1, rev3)
+	}
+	after, _, _ := m.ListRevisions(tenant, "", "", 200)
+	if len(after) != len(before) {
+		t.Fatalf("duplicate raw rows should not create revision, before=%d after=%d", len(before), len(after))
+	}
+}
+
+func TestHashAggregatedMaterialization_DedupesIdenticalRows(t *testing.T) {
+	rows := []store.PrefixRow{
+		{Prefix: "10.0.0.0/24", Source: "ip_range"},
+		{Prefix: "10.0.0.0/24", Source: "ip_range"},
+	}
+	h1 := hashAggregatedMaterialization("tenant-a", rows)
+	h2 := hashAggregatedMaterialization("tenant-a", []store.PrefixRow{
+		{Prefix: "10.0.0.0/24", Source: "ip_range"},
+	})
+	if h1 != h2 {
+		t.Fatalf("expected deduped hash to match, got %s vs %s", h1, h2)
+	}
+}