move hive-sh4re's paused_marker() composition into hive-agent

hive-agent/src/main.rs

@@ -686,7 +686,7 @@ async fn serve_loop<S: Surface>(
         // need to be: hive-c0re skips the stop-checkpoint handshake for
         // a paused agent, because this check sits at the top of the loop
         // and so a paused agent provably has no turn in flight.
-        if hive_sh4re::paths::paused_marker().exists() {
+        if paths::paused_marker().exists() {
             if !was_paused {
                 tracing::info!("pause marker present — parking the turn loop");
                 bus.emit(LiveEvent::Note {
@@ -827,7 +827,7 @@ fn apply_todo_wake_checked(checked: Option<bool>, todo_miss_streak: &mut u32, bu
                          consecutive todo wakes — an operator needs to resume this agent"
                     ),
                 });
-                if let Err(e) = std::fs::write(hive_sh4re::paths::paused_marker(), "") {
+                if let Err(e) = std::fs::write(paths::paused_marker(), "") {
                     tracing::warn!(error = ?e, "failed to write pause marker");
                 }
                 // Fresh slate for whenever this agent gets resumed — see

hive-agent/src/paths.rs

@@ -90,6 +90,29 @@ pub fn config_dir() -> PathBuf {
     PathBuf::from("/run/hive-config")
 }
 
+/// Marker file whose presence means "this agent is paused": the harness
+/// keeps serving its web UI and MCP daemons but drives no turns, so
+/// inbox messages queue up unacked until it's removed.
+///
+/// It lives in the harness dir rather than `state/` because `state/` is
+/// the agent's own scratch space — this is harness control state. The
+/// harness dir is bind-mounted from the host, so the marker is the
+/// single source of truth for both sides: the harness stats it to gate
+/// the turn loop, and hive-c0re stats it to render the paused
+/// indicator and creates/removes it for `hivectl pause|resume`. Being a
+/// plain file, it survives container restarts — pause is sticky by
+/// construction, and works even when the harness isn't running.
+/// The filename constant is shared via `hive_sh4re::paths::PAUSED_MARKER_FILE`
+/// (itself re-exported from `hive-priv-sock`, the actual writer on the host
+/// side) so this resolver and hive-c0re's host-side one
+/// (`Coordinator::agent_paused_marker`) cannot drift apart — only the
+/// call-site-specific composition lived in the shared crate for no reason,
+/// since hive-agent is the only in-container caller.
+#[must_use]
+pub fn paused_marker() -> PathBuf {
+    harness_dir().join(hive_sh4re::paths::PAUSED_MARKER_FILE)
+}
+
 /// Claude credentials directory for the current agent. `$HOME/.claude`
 /// matches what the `claude` CLI reads at runtime — the harness sees
 /// the same `$HOME` set by the per-service systemd `environment`