Backfill channel sender identity when it's available

frontend/src/App.tsx

@@ -84,6 +84,7 @@ export function App() {
   const [crackerRunning, setCrackerRunning] = useState(false);
   const [localLabel, setLocalLabel] = useState(getLocalLabel);
   const [infoPaneContactKey, setInfoPaneContactKey] = useState<string | null>(null);
+  const [infoPaneFromChannel, setInfoPaneFromChannel] = useState(false);
   const [infoPaneChannelKey, setInfoPaneChannelKey] = useState<string | null>(null);
   const [targetMessageId, setTargetMessageId] = useState<number | null>(null);
 
@@ -523,8 +524,9 @@ export function App() {
     setShowCracker((prev) => !prev);
   }, []);
 
-  const handleOpenContactInfo = useCallback((publicKey: string) => {
+  const handleOpenContactInfo = useCallback((publicKey: string, fromChannel?: boolean) => {
     setInfoPaneContactKey(publicKey);
+    setInfoPaneFromChannel(fromChannel ?? false);
   }, []);
 
   const handleCloseContactInfo = useCallback(() => {
@@ -934,6 +936,7 @@ export function App() {
 
       <ContactInfoPane
         contactKey={infoPaneContactKey}
+        fromChannel={infoPaneFromChannel}
         onClose={handleCloseContactInfo}
         contacts={contacts}
         config={config}

frontend/src/components/ContactInfoPane.tsx

@@ -20,6 +20,7 @@ const CONTACT_TYPE_LABELS: Record<number, string> = {
 
 interface ContactInfoPaneProps {
   contactKey: string | null;
+  fromChannel?: boolean;
   onClose: () => void;
   contacts: Contact[];
   config: RadioConfig | null;
@@ -34,6 +35,7 @@ interface ContactInfoPaneProps {
 
 export function ContactInfoPane({
   contactKey,
+  fromChannel = false,
   onClose,
   contacts,
   config,
@@ -117,6 +119,8 @@ export function ContactInfoPane({
               </div>
             </div>
 
+            {fromChannel && <ChannelAttributionWarning />}
+
             {/* Block by name toggle */}
             {onToggleBlockedName && (
               <div className="px-5 py-3 border-b border-border">
@@ -186,6 +190,8 @@ export function ContactInfoPane({
               </div>
             </div>
 
+            {fromChannel && <ChannelAttributionWarning />}
+
             {/* Info grid */}
             <div className="px-5 py-3 border-b border-border">
               <div className="grid grid-cols-2 gap-x-4 gap-y-2 text-sm">
@@ -436,6 +442,18 @@ function SectionLabel({ children }: { children: React.ReactNode }) {
   );
 }
 
+function ChannelAttributionWarning() {
+  return (
+    <div className="mx-5 my-3 px-3 py-2 rounded-md bg-yellow-500/10 border border-yellow-500/20">
+      <p className="text-xs text-yellow-600 dark:text-yellow-400">
+        Channel sender identity is based on best-effort name matching. Different nodes using the
+        same name will be attributed to the same contact. Message counts and key-based statistics
+        may be inaccurate.
+      </p>
+    </div>
+  );
+}
+
 function InfoItem({ label, value }: { label: string; value: string }) {
   return (
     <div>

frontend/src/components/MessageList.tsx

@@ -27,7 +27,7 @@ interface MessageListProps {
   onResendChannelMessage?: (messageId: number, newTimestamp?: boolean) => void;
   radioName?: string;
   config?: RadioConfig | null;
-  onOpenContactInfo?: (publicKey: string) => void;
+  onOpenContactInfo?: (publicKey: string, fromChannel?: boolean) => void;
   targetMessageId?: number | null;
   onTargetReached?: () => void;
   hasNewerMessages?: boolean;
@@ -532,7 +532,11 @@ export function MessageList({
                       role={onOpenContactInfo ? 'button' : undefined}
                       tabIndex={onOpenContactInfo ? 0 : undefined}
                       onKeyDown={onOpenContactInfo ? handleKeyboardActivate : undefined}
-                      onClick={onOpenContactInfo ? () => onOpenContactInfo(avatarKey) : undefined}
+                      onClick={
+                        onOpenContactInfo
+                          ? () => onOpenContactInfo(avatarKey, msg.type === 'CHAN')
+                          : undefined
+                      }
                     >
                       <ContactAvatar
                         name={avatarName}