fix(#1164,#1171): harness writes status file, c0re just rescans

hive-ag3nt/src/mcp.rs

@@ -102,6 +102,51 @@ impl From<hive_sh4re::Response> for SocketReply {
     }
 }
 
+/// Write (or remove) the status file in the agent's own `state/` directory.
+/// Called by both `AgentServer::set_status` and `ManagerServer::set_status`
+/// before dispatching the wire `SetStatus` request (which only triggers a
+/// dashboard rescan on the host side — file I/O moved here because the
+/// harness runs as the agent user and has write access to `state/`, whereas
+/// hive-c0re's `hive-core` user does not after the privsep migration).
+///
+/// Mirrors the validation in `hive-c0re::limits::check_status_text` so
+/// the file is never written with text the server would later reject (which
+/// would leave a stale invalid entry on disk).
+fn write_status_file(text: &str) -> Result<(), String> {
+    let trimmed = text.trim();
+    if !trimmed.is_empty() {
+        if trimmed.contains('\n') || trimmed.contains('\r') {
+            return Err(
+                "set_status text must be a single line — write multi-line context to \
+                 a file under your state/ dir and reference that path from the chip instead"
+                    .to_owned(),
+            );
+        }
+        // 200 chars mirrors STATUS_MAX_CHARS in hive-c0re/src/limits.rs.
+        // Keep in sync if that constant changes.
+        const STATUS_MAX_CHARS: usize = 200;
+        let len = trimmed.chars().count();
+        if len > STATUS_MAX_CHARS {
+            return Err(format!(
+                "set_status text too long ({len} chars, max {STATUS_MAX_CHARS}); trim to a short summary"
+            ));
+        }
+    }
+    let path = crate::paths::state_dir().join("hyperhive-status");
+    let result = if trimmed.is_empty() {
+        std::fs::remove_file(&path).or_else(|e| {
+            if e.kind() == std::io::ErrorKind::NotFound {
+                Ok(())
+            } else {
+                Err(e)
+            }
+        })
+    } else {
+        std::fs::write(&path, format!("{trimmed}\n"))
+    };
+    result.map_err(|e| format!("set_status write failed: {e}"))
+}
+
 /// Format helper for "send-like" tools (anything that expects an `Ok`).
 /// `tool` and `ok_msg` only appear in the result string; they don't change
 /// behavior.
@@ -763,6 +808,9 @@ impl AgentServer {
     )]
     async fn set_status(&self, Parameters(args): Parameters<SetStatusArgs>) -> String {
         run_tool_envelope("set_status", args.text.clone(), async move {
+            if let Err(e) = write_status_file(&args.text) {
+                return e;
+            }
             let (resp, retries) = self
                 .dispatch(hive_sh4re::AgentRequest::SetStatus { text: args.text })
                 .await;
@@ -1821,6 +1869,9 @@ impl ManagerServer {
     )]
     async fn set_status(&self, Parameters(args): Parameters<SetStatusArgs>) -> String {
         run_tool_envelope("set_status", args.text.clone(), async move {
+            if let Err(e) = write_status_file(&args.text) {
+                return e;
+            }
             let (resp, retries) = self
                 .dispatch(hive_sh4re::ManagerRequest::SetStatus { text: args.text })
                 .await;