Fix pagination bar disappearing on 0 results for Shiny server backends

Track the highest row count seen across server data fetches so the
pagination bar stays visible after filtering or searching reduces
results to zero. This matches the existing DuckDB WASM client behavior.

Backends that provide an explicit maxRowCount (V8) are still respected
via Math.max.

Author: glin

srcjs/Reactable.js

@@ -1236,7 +1236,10 @@ function Table({
         const { rowCount, maxRowCount } = body
         setNewData(data)
         setServerRowCount(rowCount)
-        setServerMaxRowCount(maxRowCount)
+        // Track the highest row count seen so pagination doesn't auto-hide after
+        // a search or filter reduces results to zero. Use the backend-provided
+        // maxRowCount if available (e.g., V8), otherwise track the max of rowCount.
+        setServerMaxRowCount(prev => Math.max(prev ?? 0, maxRowCount ?? rowCount))
       })
       .catch(err => {
         console.error(err)