Refactor installation and runner scripts for enhanced usability and security

- Updated the installation script to clarify that production wrappers do not include fixed test secrets, improving user guidance for local testing.
- Modified the jiggablend-manager and jiggablend-runner scripts to remove fixed test configurations, emphasizing the use of local test credentials via `make init-test`.
- Enhanced error handling in the runner script to ensure that an API key is provided, improving security and user feedback.
- Added new flags and options for the runner, including sandboxing capabilities and GPU ray tracing control, enhancing flexibility for users.
- Improved README documentation to reflect changes in usage and configuration, ensuring users have clear instructions for setup and execution.

internal/manager/runners_test.go

@@ -1,6 +1,9 @@
 package api
 
-import "testing"
+import (
+	"encoding/json"
+	"testing"
+)
 
 func TestParseBlenderFrame(t *testing.T) {
 	frame, ok := parseBlenderFrame("Info Fra:2470 Mem:12.00M")
@@ -19,3 +22,79 @@ func TestJobTaskCounts_Progress(t *testing.T) {
 	}
 }
 
+func TestParseWSTaskUpdate_LegacyErrorObject(t *testing.T) {
+	// Simulates older runners that JSON-marshaled an error interface as {}
+	raw := json.RawMessage(`{"task_id":99,"success":false,"error":{}}`)
+	update, err := parseWSTaskUpdate(raw)
+	if err != nil {
+		t.Fatalf("parseWSTaskUpdate: %v", err)
+	}
+	if update.TaskID != 99 {
+		t.Fatalf("TaskID = %d, want 99", update.TaskID)
+	}
+	if update.Success {
+		t.Fatal("Success = true, want false")
+	}
+	if update.Error != "" {
+		t.Fatalf("Error = %q, want empty (legacy object)", update.Error)
+	}
+}
+
+func TestParseWSTaskUpdate_StringError(t *testing.T) {
+	raw := json.RawMessage(`{"task_id":7,"success":false,"error":"blender failed: signal: segmentation fault (core dumped)","free_requeue":true}`)
+	update, err := parseWSTaskUpdate(raw)
+	if err != nil {
+		t.Fatalf("parseWSTaskUpdate: %v", err)
+	}
+	if update.TaskID != 7 || update.Success {
+		t.Fatalf("unexpected update: %+v", update)
+	}
+	if update.Error != "blender failed: signal: segmentation fault (core dumped)" {
+		t.Fatalf("Error = %q", update.Error)
+	}
+	if !update.FreeRequeue {
+		t.Fatal("expected FreeRequeue true")
+	}
+}
+
+func TestFormatInferredTaskFailure(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{
+			name: "task failed segfault prefix",
+			in:   "Task failed: blender failed: signal: segmentation fault (core dumped)",
+			want: "blender failed: signal: segmentation fault (core dumped)",
+		},
+		{
+			name: "blender render failed prefix",
+			in:   "Blender render failed: blender failed: signal: segmentation fault (core dumped)",
+			want: "blender failed: signal: segmentation fault (core dumped)",
+		},
+		{
+			name: "double prefix",
+			in:   "Task failed: Blender render failed: blender failed: signal: segmentation fault (core dumped)",
+			want: "blender failed: signal: segmentation fault (core dumped)",
+		},
+		{
+			name: "plain message",
+			in:   "blender failed: exit status 1",
+			want: "blender failed: exit status 1",
+		},
+		{
+			name: "empty falls back",
+			in:   "   ",
+			want: defaultUnexpectedDisconnectError,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := formatInferredTaskFailure(tt.in); got != tt.want {
+				t.Fatalf("formatInferredTaskFailure(%q) = %q, want %q", tt.in, got, tt.want)
+			}
+		})
+	}
+}
+