feat(shipote): throughput + stats persistente + auth peer (fase P)

- FlowMeter (atomic u64 + rolling window 32 samples) en cada FlowChannel.
  flow_throughput() → (socket, bytes_total, bytes_per_sec). CLI:
  shipote flow throughput. Idle threshold 5s = rate 0.0.
- Snapshot v4 con stats_history persistente por workspace (cap 16).
  PersistedStats separado para evitar Instant. Restore hidrata el VecDeque
  con source="persisted".
- Auth SO_PEERCRED: daemon rechaza peers con uid distinto al propio.
  SHIPOTE_TRUST_ANYONE=1 = escape hatch documentado.

84 tests pasan (ente-incarnate 16, nouser-core 27, shipote-card 8,
shipote-core 25, shipote-discern 5, yahweh-provider-fs 3).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

crates/apps/shipote-cli/src/main.rs

@@ -87,6 +87,8 @@ enum Cmd {
 enum FlowCmd {
     /// Listar pipelines activos con sus sockets de flow.
     List,
+    /// Throughput por flow socket (bytes_total + bytes/s).
+    Throughput,
     /// Cerrar el data plane de un pipeline (drop de todos sus sockets).
     Drop { pipeline: String },
     /// Suscribirse a un flow socket y volcar bytes a stdout.
@@ -557,6 +559,26 @@ async fn main() -> Result<()> {
             }
         }
 
+        Cmd::Flow(FlowCmd::Throughput) => {
+            let resp = round_trip(&mut stream, Request::FlowThroughput).await?;
+            match resp {
+                Response::FlowThroughput { items } => {
+                    if items.is_empty() {
+                        println!("(no active flows)");
+                    }
+                    for it in items {
+                        let name = it.socket.file_name()
+                            .map(|n| n.to_string_lossy().to_string())
+                            .unwrap_or_else(|| it.socket.display().to_string());
+                        let kib = it.bytes_total as f64 / 1024.0;
+                        let kbs = it.bytes_per_sec / 1024.0;
+                        println!("{:<60} {:>8.1} KiB total  {:>8.2} KiB/s", name, kib, kbs);
+                    }
+                }
+                other => print_unexpected(&other),
+            }
+        }
+
         Cmd::Flow(FlowCmd::Drop { pipeline }) => {
             let pid = Ulid::from_string(&pipeline).map_err(|e| anyhow!("invalid pipeline id: {e}"))?;
             let resp = round_trip(&mut stream, Request::FlowDrop { pipeline: pid }).await?;