refactor: standardize timing with monotonic clocks, remove redundant stream parsing

src/pygui/backend/controllers/session_controller.py

@@ -1,6 +1,7 @@
 """QML-facing controller for the live/review wafer dashboard."""
 from __future__ import annotations
 import logging
+import time
 from typing import Any, Optional
 
 from PySide6.QtCore import QObject, Property, QTimer, Qt, Signal, Slot
@@ -325,10 +326,7 @@ class SessionController(QObject):
                     result = -result
                 values.append(result)
             
-            # Create a mock timestamp or use elapsed time since start.
-            # We don't have a time value from the binary stream header right now.
-            t = seq * 0.05  # approx 20Hz if seq increments 1 per frame
-            return Frame(seq=seq, time=t, values=values)
+            return Frame(seq=seq, time=time.monotonic(), values=values)
 
         # Clear out any old data from the prev sessions
         self._model.reset()