diff --git a/tests/unit/security/audit_test.go b/internal/security/audit_test.go
similarity index 99%
rename from tests/unit/security/audit_test.go
rename to internal/security/audit_test.go
index 01888ea..85e8102 100644
--- a/tests/unit/security/audit_test.go
+++ b/internal/security/audit_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"log/slog"
diff --git a/tests/unit/security/config_integrity_test.go b/internal/security/config_integrity_test.go
similarity index 99%
rename from tests/unit/security/config_integrity_test.go
rename to internal/security/config_integrity_test.go
index c1a4c3a..5656e41 100644
--- a/tests/unit/security/config_integrity_test.go
+++ b/internal/security/config_integrity_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"os"
diff --git a/tests/unit/security/filetype_test.go b/internal/security/filetype_test.go
similarity index 99%
rename from tests/unit/security/filetype_test.go
rename to internal/security/filetype_test.go
index 6fc7b2c..ae7e0b4 100644
--- a/tests/unit/security/filetype_test.go
+++ b/internal/security/filetype_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"os"
diff --git a/tests/unit/security/gpu_audit_test.go b/internal/security/gpu_audit_test.go
similarity index 99%
rename from tests/unit/security/gpu_audit_test.go
rename to internal/security/gpu_audit_test.go
index 68f11a5..34bb493 100644
--- a/tests/unit/security/gpu_audit_test.go
+++ b/internal/security/gpu_audit_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"bytes"
diff --git a/tests/unit/security/hipaa_validation_test.go b/internal/security/hipaa_validation_test.go
similarity index 99%
rename from tests/unit/security/hipaa_validation_test.go
rename to internal/security/hipaa_validation_test.go
index b580f44..c9afb04 100644
--- a/tests/unit/security/hipaa_validation_test.go
+++ b/internal/security/hipaa_validation_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"fmt"
diff --git a/tests/unit/security/manifest_filename_test.go b/internal/security/manifest_filename_test.go
similarity index 99%
rename from tests/unit/security/manifest_filename_test.go
rename to internal/security/manifest_filename_test.go
index 2eab25c..c4dcd77 100644
--- a/tests/unit/security/manifest_filename_test.go
+++ b/internal/security/manifest_filename_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"os"
diff --git a/tests/unit/security/path_traversal_test.go b/internal/security/path_traversal_test.go
similarity index 99%
rename from tests/unit/security/path_traversal_test.go
rename to internal/security/path_traversal_test.go
index bd3645c..a820b2d 100644
--- a/tests/unit/security/path_traversal_test.go
+++ b/internal/security/path_traversal_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"os"
diff --git a/tests/unit/security/resource_quota_test.go b/internal/security/resource_quota_test.go
similarity index 99%
rename from tests/unit/security/resource_quota_test.go
rename to internal/security/resource_quota_test.go
index 5ebfd03..347b09d 100644
--- a/tests/unit/security/resource_quota_test.go
+++ b/internal/security/resource_quota_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"os"
diff --git a/tests/unit/security/secrets_test.go b/internal/security/secrets_test.go
similarity index 99%
rename from tests/unit/security/secrets_test.go
rename to internal/security/secrets_test.go
index bcb3af8..5905695 100644
--- a/tests/unit/security/secrets_test.go
+++ b/internal/security/secrets_test.go
@@ -1,4 +1,4 @@
-package security
+package security_test
 
 import (
 	"strings"
diff --git a/tests/unit/storage/db_test.go b/internal/storage/db_test.go
similarity index 99%
rename from tests/unit/storage/db_test.go
rename to internal/storage/db_test.go
index 1391761..0c7974e 100644
--- a/tests/unit/storage/db_test.go
+++ b/internal/storage/db_test.go
@@ -1,4 +1,4 @@
-package storage
+package storage_test
 
 import (
 	"os"
diff --git a/tests/unit/storage/experiment_metadata_test.go b/internal/storage/experiment_metadata_test.go
similarity index 99%
rename from tests/unit/storage/experiment_metadata_test.go
rename to internal/storage/experiment_metadata_test.go
index 8096e2a..9ae99f1 100644
--- a/tests/unit/storage/experiment_metadata_test.go
+++ b/internal/storage/experiment_metadata_test.go
@@ -1,4 +1,4 @@
-package storage
+package storage_test
 
 import (
 	"context"
diff --git a/tests/unit/telemetry/telemetry_test.go b/internal/telemetry/telemetry_test.go
similarity index 99%
rename from tests/unit/telemetry/telemetry_test.go
rename to internal/telemetry/telemetry_test.go
index 03192dc..8da1b45 100644
--- a/tests/unit/telemetry/telemetry_test.go
+++ b/internal/telemetry/telemetry_test.go
@@ -1,4 +1,4 @@
-package telemetry
+package telemetry_test
 
 import (
 	"testing"
diff --git a/tests/unit/reproducibility/config_hash_test.go b/internal/tracking/config_hash_test.go
similarity index 99%
rename from tests/unit/reproducibility/config_hash_test.go
rename to internal/tracking/config_hash_test.go
index 5fd2c3f..dfd2d8f 100644
--- a/tests/unit/reproducibility/config_hash_test.go
+++ b/internal/tracking/config_hash_test.go
@@ -1,4 +1,4 @@
-package reproducibility
+package tracking_test
 
 import (
 	"os"
diff --git a/tests/unit/reproducibility/environment_capture_test.go b/internal/tracking/environment_capture_test.go
similarity index 99%
rename from tests/unit/reproducibility/environment_capture_test.go
rename to internal/tracking/environment_capture_test.go
index a07025f..1f86c85 100644
--- a/tests/unit/reproducibility/environment_capture_test.go
+++ b/internal/tracking/environment_capture_test.go
@@ -1,4 +1,4 @@
-package reproducibility
+package tracking_test
 
 import (
 	"os"
diff --git a/tests/unit/worker/artifacts_test.go b/internal/worker/artifacts_test.go
similarity index 100%
rename from tests/unit/worker/artifacts_test.go
rename to internal/worker/artifacts_test.go
diff --git a/tests/unit/worker/config_test.go b/internal/worker/config_test.go
similarity index 100%
rename from tests/unit/worker/config_test.go
rename to internal/worker/config_test.go
diff --git a/internal/worker/gpu_detector.go b/internal/worker/gpu_detector.go
index cc53f60..ed3b4bf 100644
--- a/internal/worker/gpu_detector.go
+++ b/internal/worker/gpu_detector.go
@@ -1,6 +1,7 @@
 package worker
 
 import (
+	"errors"
 	"fmt"
 	"log/slog"
 	"os"
@@ -184,6 +185,24 @@ type DetectionResult struct {
 	Info     GPUDetectionInfo
 }
 
+// Validate checks if the detection result is valid and returns an error if not.
+// This ensures users get clear error messages for unimplemented features like AMD GPU.
+func (r DetectionResult) Validate() error {
+	if r.Detector == nil {
+		switch r.Info.ConfiguredVendor {
+		case "amd":
+			return errors.New(
+				"AMD GPU support is not yet implemented. " +
+					"Use NVIDIA GPUs, Apple Silicon, or CPU-only mode. " +
+					"For development/testing, use FETCH_ML_MOCK_GPU_TYPE=AMD",
+			)
+		default:
+			return fmt.Errorf("GPU detection failed for vendor %q", r.Info.ConfiguredVendor)
+		}
+	}
+	return nil
+}
+
 func (f *GPUDetectorFactory) CreateDetector(cfg *Config) GPUDetector {
 	result := f.CreateDetectorWithInfo(cfg)
 	return result.Detector
@@ -233,9 +252,10 @@ func (f *GPUDetectorFactory) CreateDetectorWithInfo(cfg *Config) DetectionResult
 				},
 			}
 		case "amd":
-			// AMD env override uses NVIDIA detector (aliased)
+			// AMD GPU support not yet implemented
+			// Return error so user knows this is a known limitation
 			return DetectionResult{
-				Detector: &NVIDIADetector{},
+				Detector: nil, // Will cause error when used
 				Info: GPUDetectionInfo{
 					GPUType:          GPUTypeAMD,
 					ConfiguredVendor: "amd",
@@ -295,9 +315,9 @@ func (f *GPUDetectorFactory) CreateDetectorWithInfo(cfg *Config) DetectionResult
 				},
 			}
 		case "amd":
-			// AMD env override uses NVIDIA detector (aliased)
+			// AMD GPU support not yet implemented
 			return DetectionResult{
-				Detector: &NVIDIADetector{},
+				Detector: nil,
 				Info: GPUDetectionInfo{
 					GPUType:          GPUTypeAMD,
 					ConfiguredVendor: "amd",
@@ -388,14 +408,13 @@ func (f *GPUDetectorFactory) detectFromConfigWithSource(cfg *Config, source Dete
 			},
 		}
 	case "amd":
-		// AMD uses similar device exposure patterns in this codebase.
-		// This is the key aliasing point - we report AMD as configured vendor
-		// but use NVIDIADetector for implementation.
+		// AMD GPU support not yet implemented - tracked in roadmap
+		logWarningf("AMD GPU detection requested but not yet implemented. Consider using MOCK mode or contributing to the project.")
 		return DetectionResult{
-			Detector: &NVIDIADetector{},
+			Detector: nil,
 			Info: GPUDetectionInfo{
-				GPUType:                 GPUTypeNVIDIA,
-				ConfiguredVendor:        "amd", // User configured "amd"
+				GPUType:                 GPUTypeAMD,
+				ConfiguredVendor:        "amd",
 				DetectionMethod:         source,
 				EnvOverrideType:         envType,
 				EnvOverrideCount:        envCount,
@@ -491,9 +510,9 @@ func DetectCapabilities() scheduler.WorkerCapabilities {
 				MemoryGB:   getSystemMemoryGB(),
 				Hostname:   getHostname(),
 				GPUInfo: scheduler.GPUDetectionInfo{
-					GPUType:  "vulkan",
-					Count:    count,
-					Devices:  getVulkanDevices(),
+					GPUType: "vulkan",
+					Count:   count,
+					Devices: getVulkanDevices(),
 				},
 			}
 		}
diff --git a/tests/unit/worker/hash_bench_test.go b/internal/worker/hash_bench_test.go
similarity index 100%
rename from tests/unit/worker/hash_bench_test.go
rename to internal/worker/hash_bench_test.go
diff --git a/tests/unit/worker/plugins/jupyter_task_test.go b/internal/worker/plugins/jupyter_task_test.go
similarity index 99%
rename from tests/unit/worker/plugins/jupyter_task_test.go
rename to internal/worker/plugins/jupyter_task_test.go
index b3f3e6a..137e039 100644
--- a/tests/unit/worker/plugins/jupyter_task_test.go
+++ b/internal/worker/plugins/jupyter_task_test.go
@@ -1,4 +1,4 @@
-package plugins__test
+package plugins_test
 
 import (
 	"context"
diff --git a/tests/unit/worker/plugins/vllm_test.go b/internal/worker/plugins/vllm_test.go
similarity index 99%
rename from tests/unit/worker/plugins/vllm_test.go
rename to internal/worker/plugins/vllm_test.go
index 9eb39b0..3256ddc 100644
--- a/tests/unit/worker/plugins/vllm_test.go
+++ b/internal/worker/plugins/vllm_test.go
@@ -1,4 +1,4 @@
-package plugins__test
+package plugins_test
 
 import (
 	"context"
diff --git a/tests/unit/worker/prewarm_v1_test.go b/internal/worker/prewarm_v1_test.go
similarity index 100%
rename from tests/unit/worker/prewarm_v1_test.go
rename to internal/worker/prewarm_v1_test.go
diff --git a/tests/unit/worker/run_manifest_execution_test.go b/internal/worker/run_manifest_execution_test.go
similarity index 100%
rename from tests/unit/worker/run_manifest_execution_test.go
rename to internal/worker/run_manifest_execution_test.go
diff --git a/tests/unit/worker/snapshot_stage_test.go b/internal/worker/snapshot_stage_test.go
similarity index 100%
rename from tests/unit/worker/snapshot_stage_test.go
rename to internal/worker/snapshot_stage_test.go
diff --git a/tests/unit/worker/snapshot_store_test.go b/internal/worker/snapshot_store_test.go
similarity index 100%
rename from tests/unit/worker/snapshot_store_test.go
rename to internal/worker/snapshot_store_test.go
diff --git a/tests/unit/worker/worker_test.go b/internal/worker/worker_test.go
similarity index 100%
rename from tests/unit/worker/worker_test.go
rename to internal/worker/worker_test.go