feat(webhooks): add webhook fields to frontend types, api, and edit sheet

k-tv-frontend/app/(main)/dashboard/components/edit-channel-sheet.tsx

@@ -756,6 +756,8 @@ interface EditChannelSheetProps {
       logo?: string | null;
       logo_position?: LogoPosition;
       logo_opacity?: number;
+      webhook_url?: string | null;
+      webhook_poll_interval_secs?: number;
     },
   ) => void;
   isPending: boolean;
@@ -787,6 +789,8 @@ export function EditChannelSheet({
   const [logo, setLogo] = useState<string | null>(null);
   const [logoPosition, setLogoPosition] = useState<LogoPosition>("top_right");
   const [logoOpacity, setLogoOpacity] = useState(100);
+  const [webhookUrl, setWebhookUrl] = useState("");
+  const [webhookPollInterval, setWebhookPollInterval] = useState<number | "">(5);
   const [selectedBlockId, setSelectedBlockId] = useState<string | null>(null);
   const [fieldErrors, setFieldErrors] = useState<FieldErrors>({});
   const fileInputRef = useRef<HTMLInputElement>(null);
@@ -804,6 +808,8 @@ export function EditChannelSheet({
       setLogo(channel.logo ?? null);
       setLogoPosition(channel.logo_position ?? "top_right");
       setLogoOpacity(Math.round((channel.logo_opacity ?? 1) * 100));
+      setWebhookUrl(channel.webhook_url ?? "");
+      setWebhookPollInterval(channel.webhook_poll_interval_secs ?? 5);
       setSelectedBlockId(null);
       setFieldErrors({});
     }
@@ -836,6 +842,10 @@ export function EditChannelSheet({
       logo: logo,
       logo_position: logoPosition,
       logo_opacity: logoOpacity / 100,
+      webhook_url: webhookUrl || null,
+      ...(webhookUrl
+        ? { webhook_poll_interval_secs: webhookPollInterval === "" ? 5 : webhookPollInterval }
+        : {}),
     });
   };
 
@@ -1085,6 +1095,28 @@ export function EditChannelSheet({
                 onChange={setRecyclePolicy}
               />
             </section>
+
+            {/* Webhook */}
+            <section className="space-y-3">
+              <h3 className="text-xs font-semibold uppercase tracking-wider text-zinc-500">Webhook</h3>
+              <Field label="Webhook URL" hint="POST events to this URL on broadcast changes">
+                <TextInput
+                  value={webhookUrl}
+                  onChange={setWebhookUrl}
+                  placeholder="https://example.com/webhook"
+                />
+              </Field>
+              {webhookUrl && (
+                <Field label="Poll interval (seconds)" hint="How often to check for broadcast changes">
+                  <NumberInput
+                    value={webhookPollInterval}
+                    onChange={setWebhookPollInterval}
+                    min={1}
+                    placeholder="5"
+                  />
+                </Field>
+              )}
+            </section>
           </div>
 
           {/* Footer */}