iceberg: let table properties override the worker config (#10772)

* iceberg: carry snapshot retention in milliseconds

Config stored retention as hours, so any sub-hour value would have to be
truncated to 0 and then clamped back up to the 168 hour default. Keep the
plugin config key in hours and convert once at parse time.

* iceberg: let table properties override the worker config

Every other Iceberg implementation lets a table's own properties win over
engine defaults; the worker ignored them entirely. A writer honouring
write.target-file-size-bytes and a compactor rewriting to the plugin
config's size would rewrite each other's output forever.

Resolved once per job rather than per operation, so compaction committing
new metadata mid-job cannot change the settings underneath it.

* iceberg: clamp the orphan cutoff so it cannot overflow

collectOrphanCandidates converts the cutoff to a time.Duration. Past
roughly 2.5 million hours that multiplication wraps negative, putting the
cutoff in the future so every file walked looks like an orphan and gets
deleted, including data a concurrent writer has not yet committed.

Reachable today through orphan_older_than_hours.

test/s3tables/maintenance/maintenance_integration_test.go

@@ -600,9 +600,9 @@ func testExpireSnapshots(t *testing.T) {
 
 	handler := icebergHandler.NewHandler(nil)
 	config := icebergHandler.Config{
-		SnapshotRetentionHours: 0, // instant expiry — everything eligible
-		MaxSnapshotsToKeep:     1, // keep only the current snapshot
-		MaxCommitRetries:       3,
+		SnapshotRetentionMs: 0, // instant expiry — everything eligible
+		MaxSnapshotsToKeep:  1, // keep only the current snapshot
+		MaxCommitRetries:    3,
 	}
 
 	result, _, err := handler.ExpireSnapshots(context.Background(), client, bucket, path.Join(ns, tbl), config)
@@ -932,9 +932,9 @@ func testFullMaintenanceCycle(t *testing.T) {
 
 	// Step 1: Expire snapshots
 	expireConfig := icebergHandler.Config{
-		SnapshotRetentionHours: 0, // instant expiry
-		MaxSnapshotsToKeep:     1,
-		MaxCommitRetries:       3,
+		SnapshotRetentionMs: 0, // instant expiry
+		MaxSnapshotsToKeep:  1,
+		MaxCommitRetries:    3,
 	}
 	result, _, err := handler.ExpireSnapshots(ctx, client, bucket, tablePath, expireConfig)
 	require.NoError(t, err)