hivectl/dashboard: add --paused / ?paused=1 to agent start

hivectl/src/cli.rs

@@ -471,7 +471,15 @@ pub enum AgentCmd {
     /// Start this EXISTING agent container. Fails immediately if `name`
     /// has no config/topology entry at all — it never attempts
     /// first-time creation. Use `create` for that.
-    Start,
+    Start {
+        /// Start (or leave) the agent paused: if it's currently down, the
+        /// pause marker is written before the container boots, so it comes
+        /// up paused instead of driving turns immediately. If it's already
+        /// running, this pauses it in place and does not attempt a
+        /// (re)start.
+        #[arg(long)]
+        paused: bool,
+    },
     /// Create this agent container from scratch (full first-time
     /// provisioning), bypassing the approval queue.
     ///