feat(webhooks): paginate list + call-history endpoints (server + web UI) (#1268)

Add total-count pagination to the webhook admin endpoints and the web UI.

Store:
- WebhookStore/WebhookCallStore gain Count; WebhookListFilter gains
  IncludeRevoked + Query (PG + SQLite, parameterized, tenant-scoped)

API:
- GET /v1/webhooks and GET /v1/webhooks/{id}/calls return
  {items, total, limit, offset} with server-side search + revoked filtering

Web UI:
- server-driven list pager + search/revoked filter; call-history dialog uses
  the real total (fixes the full-page "has more" boundary bug)
- i18n pager labels (en/vi/zh)

Tests: store pagination integration test; mock stores implement Count.
No schema migration (read-only COUNT).

tests/integration/webhook_pagination_test.go

@@ -0,0 +1,85 @@
+//go:build integration
+
+package integration
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/nextlevelbuilder/goclaw/internal/store"
+	"github.com/nextlevelbuilder/goclaw/internal/store/pg"
+)
+
+func TestWebhookListPaginationAndCount(t *testing.T) {
+	db := testDB(t)
+	tenantID, _ := seedTenantAgent(t, db)
+
+	s := pg.NewPGWebhookStore(db)
+	ctx := store.WithTenantID(context.Background(), tenantID)
+
+	t.Cleanup(func() {
+		db.Exec("DELETE FROM webhooks WHERE tenant_id = $1", tenantID)
+	})
+
+	mk := func(name string, revoked bool) {
+		id := uuid.New()
+		h := sha256.Sum256([]byte(id.String()))
+		wh := &store.WebhookData{
+			ID:           id,
+			TenantID:     tenantID,
+			Name:         name,
+			Kind:         "llm",
+			SecretPrefix: "wh_test",
+			SecretHash:   hex.EncodeToString(h[:]),
+			Revoked:      revoked,
+		}
+		if err := s.Create(ctx, wh); err != nil {
+			t.Fatalf("create %s: %v", name, err)
+		}
+	}
+
+	for i := 0; i < 5; i++ {
+		mk("active-"+uuid.NewString()[:8], false)
+	}
+	for i := 0; i < 2; i++ {
+		mk("revoked-"+uuid.NewString()[:8], true)
+	}
+
+	// Count default excludes revoked → 5.
+	if total, err := s.Count(ctx, store.WebhookListFilter{}); err != nil {
+		t.Fatal(err)
+	} else if total != 5 {
+		t.Fatalf("Count default = %d, want 5", total)
+	}
+
+	// Count including revoked → 7.
+	if total, err := s.Count(ctx, store.WebhookListFilter{IncludeRevoked: true}); err != nil {
+		t.Fatal(err)
+	} else if total != 7 {
+		t.Fatalf("Count includeRevoked = %d, want 7", total)
+	}
+
+	// Page 1 (limit 2, offset 0) → 2 rows.
+	if page1, err := s.List(ctx, store.WebhookListFilter{Limit: 2, Offset: 0}); err != nil {
+		t.Fatal(err)
+	} else if len(page1) != 2 {
+		t.Fatalf("page1 len = %d, want 2", len(page1))
+	}
+
+	// Page 3 (limit 2, offset 4) → 1 row (5 active total, revoked excluded).
+	if page3, err := s.List(ctx, store.WebhookListFilter{Limit: 2, Offset: 4}); err != nil {
+		t.Fatal(err)
+	} else if len(page3) != 1 {
+		t.Fatalf("page3 len = %d, want 1", len(page3))
+	}
+
+	// Query filter narrows Count to the 5 active "active-" rows.
+	if qc, err := s.Count(ctx, store.WebhookListFilter{Query: "active-"}); err != nil {
+		t.Fatal(err)
+	} else if qc != 5 {
+		t.Fatalf("query Count = %d, want 5", qc)
+	}
+}