Miscellaneous fixes (#23082)

* openvino log message and preview directory checks

* restrict config vars for viewer users

* recording timestamp fix

when startTime is exactly on an hour boundary, findIndex returns the first matching chunk, which is the previous hour's chunk (where before == startTime), instead of the correct chunk (where after == startTime)

the bug shows up when using the share timestamp feature and sharing a specific timestamp on the exact hour mark. when accessing the shared link, the timeline would jump to the incorrect hour

* use helper for chunked time range

* Adjustments to contributing docs

* tweak

* Improve wording

* tweak

---------

Co-authored-by: Nicolas Mowen <nickmowen213@gmail.com>

frigate/detectors/plugins/openvino.py

@@ -52,6 +52,12 @@ class OvDetector(DetectionApi):
         self.h = detector_config.model.height
         self.w = detector_config.model.width
 
+        logger.info(
+            "Loading OpenVINO model %s on device %s",
+            detector_config.model.path,
+            detector_config.device,
+        )
+
         self.runner = OpenVINOModelRunner(
             model_path=detector_config.model.path,
             device=detector_config.device,