x:Metric: say which node wrote each sample

Each node stores histograms as running totals since it started. A sample
didn't say which node wrote it (the node was only in the id's low bits),
so a reader couldn't diff totals per node, and the console diffed across
nodes: on the three-node production cluster the delivery attempt time
read 14.7 s over the last hour against 0.7 s from the nodes' own figures.

x:Metric/get now returns nodeId alongside timestamp, both from the id.
The telemetry suite checks every sample carries it.

crates/utils/src/snowflake.rs

@@ -108,6 +108,12 @@ impl SnowflakeIdGenerator {
         (id >> (SEQUENCE_LEN + NODE_ID_LEN)) / 1000 + DEFAULT_EPOCH
     }
 
+    // inbuxa: the node that made the id, so per-node history (metric
+    // totals) can be told apart
+    pub fn to_node_id(id: u64) -> u64 {
+        id & NODE_ID_MASK
+    }
+
     #[inline(always)]
     pub fn past_id(&self, period: Duration) -> Option<u64> {
         self.epoch.elapsed().ok().map(|elapsed| {