fix(#2190): replace MANAGER_AGENT fallbacks with "operator" for attribution

- loose_ends.rs: NULL submitter on legacy approval rows → "operator"
- questions.rs: NULL submitter on cancel_loose_end → "operator"
- server.rs: HostRequest::RequestSpawn submitter → "operator"
- dashboard.rs: web-UI spawn submitter → "operator"
- socket_server.rs: submit_init_config with no declared parent → "operator"
- mcp.rs: drop MANAGER_AGENT exception from check_send_allowed; keep <parent> only

hive-c0re/src/socket_server.rs

@@ -1847,8 +1847,8 @@ pub(crate) fn submit_init_config(
             description.as_deref(),
             // `parent` is the requesting agent (becomes the new child's
             // parent); it's also the submitter the approval events route
-            // back to. No declared parent = operator/root path.
-            parent.unwrap_or(hive_sh4re::MANAGER_AGENT),
+            // back to. No declared parent = operator-initiated path.
+            parent.unwrap_or("operator"),
         )
         .map_err(|e| anyhow::anyhow!("queue approval row: {e:#}"))?;
     tracing::info!(%id, %name, "init_config approval queued");