fix(builder): abandon the load operation when a resource load times out

[joaodinissf]

Why the change

After a resource load times out, the builder silently leaves some other resource out of the index; this makes a timeout cancel the build visibly instead.

Special things to note

• Behaviour change: a load timeout while writing resource descriptions now cancels the build (rolled back, next build is a full build). On master that phase carried on with a stale index; the linking phase already cancelled this way on master, so both phases now behave the same.
• A load that always stalls longer than the timeout (300 s with no result from any worker) now fails every build instead of quietly degrading the index. An interrupted wait is still reported as a timeout; that pre-existing issue is left for a follow-up.
• Raising the timeout alone does not fix the miscount, it only makes it rarer: on master every timeout leaves the counter one short for the rest of the operation.

Change outline

The owed-result counter in ParallelLoadOperation.next():

 result = resourceQueue.poll(waitTime)
-toProcess--                       # also on timeout: counter now one short
+if result != null: toProcess--
+else: timedOut = true
 if result == null
+  if timedOut: cancel()           # toProcess = 0, shutdownNow; "remaining loads are abandoned"
   throw LoadOperationException(null, TimeoutException)

What the builder does after a timeout:

 MonitoredClusteringBuilderState
   linking loop     timeout -> log, then !hasNext() -> cancel build      (unchanged)
   writeResources   timeout -> log
-                    loop ends when hasNext() is false: rest silently unindexed
+                    isAbandonedByTimeout(ex, loadOperation) -> OperationCanceledException

Tests (ParallelResourceLoaderTest, each run against an unbounded queue and production's synchronous hand-off):

• timeoutAbandonsEveryOutstandingLoad: one timeout ends the operation and queued loads never start. Fails on master.
• failedLoadDoesNotAbandonTheOperation: an ordinary load failure keeps the other loads.
• resultWithinTimeoutIsDelivered: sanity check.
• BuilderLoadTimeoutTest: only a timeout with nothing left to load counts as abandonment; a timeout with loads left, an ordinary load failure and other wrapped exceptions do not.

🤖 Generated with Claude Code

[rubenporras]

I do not get the point of this PR, could we not just increase the timeout if we want to try longer?