feat: support image quality control

apps/api/internal/runner/param_processor_test.go

@@ -660,3 +660,56 @@ func TestParamProcessorImageResolutionAndOutputCount(t *testing.T) {
 		t.Fatalf("image count should be capped to 4, got %+v", processed["n"])
 	}
 }
+
+func TestParamProcessorImageQualityControl(t *testing.T) {
+	body := map[string]any{
+		"model":   "mock-image",
+		"prompt":  "draw",
+		"quality": "high",
+	}
+
+	unsupported := preprocessRequestWithLog("images.generations", body, store.RuntimeModelCandidate{
+		ModelType: "image_generate",
+		Capabilities: map[string]any{
+			"image_generate": map[string]any{
+				"output_resolutions": []any{"1K"},
+			},
+		},
+	})
+	if _, ok := unsupported.Body["quality"]; ok {
+		t.Fatalf("quality should be removed when capability does not support it: %+v", unsupported.Body)
+	}
+	if len(unsupported.Log.Changes) == 0 || unsupported.Log.Changes[len(unsupported.Log.Changes)-1].CapabilityPath != "capabilities.image_generate.support_quality_control" {
+		t.Fatalf("expected quality removal to be logged against support_quality_control, got %+v", unsupported.Log.Changes)
+	}
+
+	supported := preprocessRequest("images.generations", body, store.RuntimeModelCandidate{
+		ModelType: "image_generate",
+		Capabilities: map[string]any{
+			"image_generate": map[string]any{
+				"support_quality_control": true,
+				"output_resolutions":      []any{"1K"},
+			},
+		},
+	})
+	if supported["quality"] != "high" {
+		t.Fatalf("quality should be retained when capability supports it: %+v", supported)
+	}
+
+	incompatible := preprocessRequest("images.generations", map[string]any{
+		"model":   "mock-image",
+		"prompt":  "draw",
+		"quality": "standard",
+	}, store.RuntimeModelCandidate{
+		ModelType: "image_generate",
+		Capabilities: map[string]any{
+			"image_generate": map[string]any{
+				"support_quality_control": true,
+				"output_resolutions":      []any{"1K"},
+			},
+		},
+	})
+	if _, ok := incompatible["quality"]; ok {
+		t.Fatalf("OpenAI-compatible GPT image quality should reject standard: %+v", incompatible)
+	}
+}