feat(agent): hf agent status-of <agent-id> — read another agent's status

The backend has GET /calendar/agent/status?agent_id=<id> (read an agent's
runtime status, no side effects) but the CLI only exposed `hf agent status
--set` (sets the CALLER's own status). So delegate-task / on-call-handoff
status gates — which need to check whether the RECEIVER/incoming agent is
idle before pinging/handing off — had no CLI path; agents had to guess from
is_active.

Add `hf agent status-of <agent-id>` wrapping the GET endpoint
(X-Claw-Identifier header, no token). Prints {agent_id, status}; surfaces the
backend's 404 for unknown agents so callers can fail-open/closed.

Verified on sim: `hf agent status-of plxrec2` → idle; --json → {"agent_id",
"status"}; unknown agent → 404 "Agent not found".

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/commands/agent.go

@@ -16,6 +16,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	neturl "net/url"
 	"os"
 	"strings"
 	"time"
@@ -138,3 +139,69 @@ func RunAgentStatus(args []string) {
 		"ok", "true",
 	)
 }
+
+// RunAgentStatusOf implements `hf agent status-of <agent-id>` — read ANOTHER
+// agent's current runtime status without side effects, wrapping
+// `GET /calendar/agent/status?agent_id=<id>`. Used by the delegate-task and
+// on-call-handoff status gates (which previously referenced this endpoint with
+// no CLI to reach it). Like RunAgentStatus this is header-identified, not
+// token-authed; the X-Claw-Identifier comes from CLAW_IDENTIFIER env or
+// hostname. Prints `{agent_id, status}`; backend returns 404 for unknown
+// agents so callers can fail-open or fail-closed.
+func RunAgentStatusOf(targetAgentID string) {
+	targetAgentID = strings.TrimSpace(targetAgentID)
+	if targetAgentID == "" {
+		output.Error("usage: hf agent status-of <agent-id>")
+	}
+
+	clawID := strings.TrimSpace(os.Getenv("CLAW_IDENTIFIER"))
+	if clawID == "" {
+		if h, err := os.Hostname(); err == nil {
+			clawID = h
+		}
+	}
+	if clawID == "" {
+		output.Error("CLAW_IDENTIFIER env not set and hostname() failed — set CLAW_IDENTIFIER explicitly")
+	}
+
+	cfg, err := config.Load()
+	if err != nil {
+		output.Errorf("config error: %v", err)
+	}
+
+	url := strings.TrimRight(cfg.BaseURL, "/") + "/calendar/agent/status?agent_id=" + neturl.QueryEscape(targetAgentID)
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		output.Errorf("cannot build request: %v", err)
+	}
+	req.Header.Set("X-Claw-Identifier", clawID)
+
+	client := &http.Client{Timeout: 30 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		output.Errorf("request failed: %v", err)
+	}
+	defer resp.Body.Close()
+
+	buf := new(bytes.Buffer)
+	_, _ = buf.ReadFrom(resp.Body)
+	if resp.StatusCode/100 != 2 {
+		output.Errorf("backend returned %d: %s", resp.StatusCode, buf.String())
+	}
+
+	if output.JSONMode {
+		fmt.Println(buf.String())
+		return
+	}
+	var parsed struct {
+		AgentID string `json:"agent_id"`
+		Status  string `json:"status"`
+	}
+	if err := json.Unmarshal(buf.Bytes(), &parsed); err != nil {
+		output.Errorf("cannot parse response: %v", err)
+	}
+	output.PrintKeyValue(
+		"agent_id", parsed.AgentID,
+		"status", parsed.Status,
+	)
+}