fix: report a clear cli error when no herdr server is running (#1963)

* fix: report a clear cli error when no herdr server is running

socket cli commands surfaced a raw io::Error debug string
(`Error: Os { code: 2, ... }`) when nothing was listening on the
api socket, which read like a bad --cwd path. map dead-socket
connect failures to a `server_not_running` json error carrying the
resolved socket path, printed once at the edge that surfaces the
error; recovering callers (plugin offline registry fallback, agent
start polling) recognize the marker and keep their existing
behavior.

refs #1941

* fix: map dead-socket errors on the unchecked cli request path

refs #1941

* fix: make server-not-running guidance session-aware

refs #1941

1 files changed, 7 insertions, 0 deletions

diff --git a/src/cli/agent.rs b/src/cli/agent.rs
index e48d6b3b..e1271f48 100644
--- a/src/cli/agent.rs
+++ b/src/cli/agent.rs
@@ -577,6 +577,13 @@ fn print_agent_transport_error(
     if super::protocol_mismatch_was_reported(&err) {
         return Ok(1);
     }
+    // A dead-server marker reaches here from `send_request` in the agent
+    // startup path; surface its deferred response exactly once instead of
+    // printing a second, generic transport-error line.
+    if let Some(response) = super::server_not_running_reported_response(&err) {
+        let value = serde_json::to_value(response).map_err(std::io::Error::other)?;
+        return super::print_response(&value);
+    }
     super::print_response(&cli_agent_error(request_id, code, err.to_string()))
 }