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
 	}