test(unraid): complete contract coverage and retain WS samples

servers/unraid/tail2-pose-server/app/tail2/core.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import asyncio
+import hmac
 import math
 import queue
 import threading
@@ -10,6 +11,10 @@ from typing import Any
 import numpy as np
 
 
+def valid_bearer(header: str | None, token: str) -> bool:
+    return bool(header and header.startswith("Bearer ") and hmac.compare_digest(header[7:], token))
+
+
 def finite01(value: float) -> float:
     value = float(value)
     return min(1.0, max(0.0, value)) if math.isfinite(value) else 0.0
@@ -88,4 +93,3 @@ class Frame:
     pixels: np.ndarray
     received_ns: int
     decode_ms: float
-