Add merge references and retry config

internal/core/config/validation_test.go

@@ -54,6 +54,18 @@ func TestValidateRejectsInvalidNumericFields(t *testing.T) {
 			},
 			want: "total LLM concurrency",
 		},
+		{
+			name: "negative retries",
+			mutate: func(cfg Config) Config {
+				profile := cfg.Pipelines["example"]
+				lane := profile.Artifacts["events"]
+				lane.Merge.Retries = -1
+				profile.Artifacts["events"] = lane
+				cfg.Pipelines["example"] = profile
+				return cfg
+			},
+			want: "retries",
+		},
 	}
 
 	for _, tc := range tests {
@@ -238,18 +250,6 @@ func TestValidateRejectsReferencesOnUnsupportedBindings(t *testing.T) {
 			},
 			want: []string{"example", "input", "references", "not supported"},
 		},
-		{
-			name: "merge",
-			mutate: func(cfg Config) Config {
-				profile := cfg.Pipelines["example"]
-				lane := profile.Artifacts["events"]
-				lane.Merge.References = map[string]string{"roster": "./roster.yml"}
-				profile.Artifacts["events"] = lane
-				cfg.Pipelines["example"] = profile
-				return cfg
-			},
-			want: []string{"example", "events", "merge", "references", "not supported"},
-		},
 		{
 			name: "validator",
 			mutate: func(cfg Config) Config {