fix: scope /kill <id> to current session subtree and preserve usage.cost in chat.history

- Restrict /kill <id> matching to only subagents belonging to the current
  session's agent subtree (P1 review feedback)
- Preserve nested usage.cost in chat.history sanitization so cost badges
  remain available (P2 review feedback)

.gitignore

@@ -121,3 +121,4 @@ dist/protocol.schema.json
 
 # Synthing
 **/.stfolder/
+openclaw

src/gateway/server-methods/chat.ts

@@ -352,6 +352,14 @@ function sanitizeUsage(raw: unknown): Record<string, number> | undefined {
     }
   }
 
+  // Preserve nested usage.cost when present
+  if ("cost" in u && u.cost != null && typeof u.cost === "object") {
+    const sanitizedCost = sanitizeCost(u.cost);
+    if (sanitizedCost) {
+      (out as Record<string, unknown>).cost = sanitizedCost;
+    }
+  }
+
   return Object.keys(out).length > 0 ? out : undefined;
 }
 

ui/src/ui/chat/slash-command-executor.ts

@@ -354,10 +354,10 @@ function resolveKillTargets(
     const isMatch =
       (normalizedTarget === "all" && belongsToCurrentSession) ||
       normalizedKey === normalizedTarget ||
-      (parsed?.agentId ?? "") === normalizedTarget ||
-      normalizedKey.endsWith(`:subagent:${normalizedTarget}`) ||
-      normalizedKey === `subagent:${normalizedTarget}` ||
-      (belongsToCurrentSession && normalizedKey.endsWith(`:subagent:${normalizedTarget}`));
+      (belongsToCurrentSession &&
+        ((parsed?.agentId ?? "") === normalizedTarget ||
+          normalizedKey.endsWith(`:subagent:${normalizedTarget}`) ||
+          normalizedKey === `subagent:${normalizedTarget}`));
     if (isMatch) {
       keys.add(key);
     }