feat(agent): loop detection (#152)

* feat(loop-detection): add configurable text and tool loop guards

* style(web): remove duplicate separator in bot settings

internal/conversation/flow/resolver_loop_detection_test.go

@@ -0,0 +1,51 @@
+package flow
+
+import "testing"
+
+func TestParseLoopDetectionEnabledFromMetadata(t *testing.T) {
+	tests := []struct {
+		name     string
+		payload  []byte
+		expected bool
+	}{
+		{
+			name:     "empty payload defaults to false",
+			payload:  nil,
+			expected: false,
+		},
+		{
+			name:     "invalid json defaults to false",
+			payload:  []byte("{"),
+			expected: false,
+		},
+		{
+			name:     "missing nested path defaults to false",
+			payload:  []byte(`{"features":{}}`),
+			expected: false,
+		},
+		{
+			name:     "explicit false",
+			payload:  []byte(`{"features":{"loop_detection":{"enabled":false}}}`),
+			expected: false,
+		},
+		{
+			name:     "explicit true",
+			payload:  []byte(`{"features":{"loop_detection":{"enabled":true}}}`),
+			expected: true,
+		},
+		{
+			name:     "non-boolean value defaults to false",
+			payload:  []byte(`{"features":{"loop_detection":{"enabled":"true"}}}`),
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := parseLoopDetectionEnabledFromMetadata(tt.payload)
+			if got != tt.expected {
+				t.Fatalf("expected %v, got %v", tt.expected, got)
+			}
+		})
+	}
+}