harden sensor acquisition after audit

docs/axis-validation-2026-08-16.md

@@ -4,10 +4,19 @@ The enclosure was tested with the battery end treated as the bottom of the
 reference orientation. The shared enclosure frame is +X right, +Y toward the
 top, and +Z toward the cover.
 
+## Audit clarification
+
+The timing results below validate the ESP32-C3 polling loop, not the independent
+sensor sample clocks. A subsequent review of the capture found a coherent repeated
+ADXL345 sample approximately every 27 polls, consistent with an actual device ODR
+near 96.3 Hz. This does not affect the static six-position axis result. Firmware v2
+adds ADXL345 and L3G4200D freshness/overrun status to every record so dynamic data
+can be interpreted correctly.
+
 ## Capture integrity
 
 - 50,001 consecutive samples over 500.000 seconds
-- Effective sample rate: exactly 100 Hz
+- Effective MCU polling rate: exactly 100 Hz
 - Timestamp interval: 10,000 us for every sample
 - Sequence gaps: 0
 - Axis-mapping mismatches between mapped and native columns: 0