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>

web/src/utils/timelineUtil.tsx

@@ -38,6 +38,22 @@ export function getChunkedTimeDay(timeRange: TimeRange): TimeRange[] {
   return data;
 }
 
+/**
+ * Find the chunk index that contains the given timestamp.
+ * Uses half-open intervals [after, before) for all chunks except the last,
+ * which uses a closed interval [after, before] so the terminal boundary
+ * is always reachable.
+ */
+export function findChunkIndex(chunks: TimeRange[], timestamp: number): number {
+  return chunks.findIndex((chunk, i) => {
+    const isLast = i === chunks.length - 1;
+    return (
+      chunk.after <= timestamp &&
+      (isLast ? chunk.before >= timestamp : chunk.before > timestamp)
+    );
+  });
+}
+
 export function getChunkedTimeRange(
   startTimestamp: number,
   endTimestamp: number,