fix: increase memory limit for vitest and improve test stability

- Updated test scripts in package.json to set NODE_OPTIONS for increased memory limit.
- Added safety checks for remote servers and domains in ProxyHostForm component to prevent errors.
- Refactored Notifications tests to remove unnecessary use of fake timers and improve clarity.
- Updated ProxyHosts extra tests to specify button names for better accessibility.
- Enhanced Security functional tests by centralizing translation strings and improving mock implementations.
- Adjusted test setup to suppress specific console errors related to act() warnings.
- Modified vitest configuration to limit worker usage and prevent memory issues during testing.

backend/cmd/api/main_parse_plugin_signatures_test.go

@@ -0,0 +1,54 @@
+package main
+
+import "testing"
+
+func TestParsePluginSignatures(t *testing.T) {
+	t.Run("unset env returns nil", func(t *testing.T) {
+		t.Setenv("CHARON_PLUGIN_SIGNATURES", "")
+		signatures := parsePluginSignatures()
+		if signatures != nil {
+			t.Fatalf("expected nil signatures when env is unset, got: %#v", signatures)
+		}
+	})
+
+	t.Run("invalid json returns nil", func(t *testing.T) {
+		t.Setenv("CHARON_PLUGIN_SIGNATURES", "{invalid}")
+		signatures := parsePluginSignatures()
+		if signatures != nil {
+			t.Fatalf("expected nil signatures for invalid json, got: %#v", signatures)
+		}
+	})
+
+	t.Run("invalid prefix returns nil", func(t *testing.T) {
+		t.Setenv("CHARON_PLUGIN_SIGNATURES", `{"plugin.so":"md5:deadbeef"}`)
+		signatures := parsePluginSignatures()
+		if signatures != nil {
+			t.Fatalf("expected nil signatures for invalid prefix, got: %#v", signatures)
+		}
+	})
+
+	t.Run("empty allowlist returns empty map", func(t *testing.T) {
+		t.Setenv("CHARON_PLUGIN_SIGNATURES", `{}`)
+		signatures := parsePluginSignatures()
+		if signatures == nil {
+			t.Fatal("expected non-nil empty map for strict empty allowlist")
+		}
+		if len(signatures) != 0 {
+			t.Fatalf("expected empty map, got: %#v", signatures)
+		}
+	})
+
+	t.Run("valid allowlist returns parsed map", func(t *testing.T) {
+		t.Setenv("CHARON_PLUGIN_SIGNATURES", `{"plugin-a.so":"sha256:abc123","plugin-b.so":"sha256:def456"}`)
+		signatures := parsePluginSignatures()
+		if signatures == nil {
+			t.Fatal("expected parsed signatures map, got nil")
+		}
+		if got := signatures["plugin-a.so"]; got != "sha256:abc123" {
+			t.Fatalf("unexpected plugin-a signature: %q", got)
+		}
+		if got := signatures["plugin-b.so"]; got != "sha256:def456" {
+			t.Fatalf("unexpected plugin-b signature: %q", got)
+		}
+	})
+}