Add hardware compatibility flags for CPU rendering and HIPRT control

- Introduced `--force-cpu-rendering` and `--disable-hiprt` flags to the runner command, allowing users to enforce CPU rendering and disable HIPRT acceleration.
- Updated the runner initialization and context structures to accommodate the new flags, enhancing flexibility in rendering configurations.
- Modified the rendering logic to respect these flags, improving compatibility and user control over rendering behavior in Blender.

internal/runner/tasks/processor.go

@@ -49,6 +49,10 @@ type Context struct {
 	GPUDetectionFailed bool
 	// OnGPUError is called when a GPU error line is seen in render logs; typically sets runner GPU lockout.
 	OnGPUError func()
+	// ForceCPURendering is a runner-level override that forces CPU rendering for all jobs.
+	ForceCPURendering bool
+	// DisableHIPRT is a runner-level override that disables HIPRT acceleration in Blender.
+	DisableHIPRT bool
 }
 
 // ErrJobCancelled indicates the manager-side job was cancelled during execution.
@@ -73,6 +77,8 @@ func NewContext(
 	gpuLockedOut bool,
 	hasHIP bool,
 	gpuDetectionFailed bool,
+	forceCPURendering bool,
+	disableHIPRT bool,
 	onGPUError func(),
 ) *Context {
 	if frameEnd < frameStart {
@@ -97,6 +103,8 @@ func NewContext(
 		GPULockedOut:       gpuLockedOut,
 		HasHIP:             hasHIP,
 		GPUDetectionFailed: gpuDetectionFailed,
+		ForceCPURendering:  forceCPURendering,
+		DisableHIPRT:       disableHIPRT,
 		OnGPUError:         onGPUError,
 	}
 }
@@ -182,6 +190,9 @@ func (c *Context) ShouldEnableExecution() bool {
 // (runner GPU lockout, GPU detection failed at startup for any version, metadata force_cpu,
 // or Blender < 4.x when the runner has HIP).
 func (c *Context) ShouldForceCPU() bool {
+	if c.ForceCPURendering {
+		return true
+	}
 	if c.GPULockedOut {
 		return true
 	}

internal/runner/tasks/render.go

@@ -27,8 +27,8 @@ func NewRenderProcessor() *RenderProcessor {
 
 // gpuErrorSubstrings are log line substrings that indicate a GPU backend error (matched case-insensitively); any match triggers full GPU lockout.
 var gpuErrorSubstrings = []string{
-	"illegal address in hip",  // HIP (AMD) e.g. "Illegal address in HIP" or "Illegal address in hip"
-	"hiperror",                // hipError* codes
+	"illegal address in hip", // HIP (AMD) e.g. "Illegal address in HIP" or "Illegal address in hip"
+	"hiperror",               // hipError* codes
 	"hip error",
 	"cuda error",
 	"cuerror",
@@ -107,7 +107,9 @@ func (p *RenderProcessor) Process(ctx *Context) error {
 		v := ctx.GetBlenderVersion()
 		major := parseBlenderMajor(v)
 		isPre4 := v != "" && major >= 0 && major < 4
-		if ctx.GPUDetectionFailed {
+		if ctx.ForceCPURendering {
+			ctx.Info("Runner compatibility flag is enabled: forcing CPU rendering for this job")
+		} else if ctx.GPUDetectionFailed {
 			ctx.Info("GPU backend detection failed at startup—we could not determine whether this machine has HIP (AMD) or NVIDIA GPUs, so rendering will use CPU to avoid compatibility issues")
 		} else if isPre4 && ctx.HasHIP {
 			ctx.Info("Blender < 4.x has no official HIP support: using CPU rendering only")
@@ -193,6 +195,7 @@ func (p *RenderProcessor) createRenderScript(ctx *Context, renderFormat string)
 		settingsMap = make(map[string]interface{})
 	}
 	settingsMap["force_cpu"] = ctx.ShouldForceCPU()
+	settingsMap["disable_hiprt"] = ctx.DisableHIPRT
 	settingsJSON, err := json.Marshal(settingsMap)
 	if err == nil {
 		if err := os.WriteFile(renderSettingsFilePath, settingsJSON, 0644); err != nil {