feat: GPU detection for LLM server (NVIDIA/AMD/Intel/Vulkan + CPU fallback)

- Added start-llama-server.bat with cross-brand GPU auto-detection:
  * Detection 1: nvidia-smi for NVIDIA
  * Detection 2: WMIC for AMD, Intel Arc, Intel HD/Iris/UHD
  * Detection 3: vulkaninfo as final fallback probe
  * Falls back to CPU-only build when no GPU found
- Downloaded llama-server b9947 builds:
  * Vulkan build (91 MB) - supports all GPU brands
  * CPU build (45 MB) - fallback in cpu/ subdir
- Downloaded Qwen2.5-Coder-1.5B Q4_K_M model (1.1 GB)
- Fixed run-hermes.bat polling: replaces fixed 5s timeout with
  curl-based readiness polling (up to 30 attempts, 1s apart)
- All .bat files verified: ASCII text, CRLF line terminators
- Added .gitignore for build artifacts and large binaries

src/diagnostics/stress.py

@@ -817,6 +817,7 @@ class GPUStressTester:
             component="gpu",
             backend="+".join(backend_parts),
             status=status,
+            duration_seconds=0.0,  # caller overwrites this with actual wall time
             summary="; ".join(summary_parts),
             details=details,
             errors=all_errors,
@@ -874,21 +875,15 @@ def run_all_stress_tests(
 
 def print_report(results: Dict[str, StressResult]) -> None:
     """Pretty-print test results to stdout."""
-    for component in ("ram", "cpu", "gpu"):
+    testers = {
+        "ram": RAMStressTester,
+        "cpu": CPUStressTester,
+        "gpu": GPUStressTester,
+    }
+    for component, tester_cls in testers.items():
         result = results.get(component)
         if result is not None:
-            print()
-            print(StressResult.report.__doc__)  # placeholder — will be replaced
-    # Actually use the testers' report methods
-    for component in ("ram", "cpu", "gpu"):
-        result = results.get(component)
-        if result is not None:
-            if component == "ram":
-                print(RAMStressTester().report(result))
-            elif component == "cpu":
-                print(CPUStressTester().report(result))
-            elif component == "gpu":
-                print(GPUStressTester().report(result))
+            print(tester_cls().report(result))
             print()