fix(ui): harden the Slack channel listing against malformed pages

- Keep already-read channel pages when a later page answers a 5xx
- Skip channel resources without a usable id
- Flatten the PATCH body test interface per TypeScript guidelines

ui/actions/integrations/slack.ts

@@ -342,10 +342,18 @@ export const getSlackChannels = async (
       });
 
       if (!response.ok) {
-        const message = await errorMessageFrom(
-          response,
-          `Unable to read the workspace's channels: ${response.statusText}`,
-        );
+        let message: string;
+        try {
+          message = await errorMessageFrom(
+            response,
+            `Unable to read the workspace's channels: ${response.statusText}`,
+          );
+        } catch (error) {
+          // `handleApiResponse` reported the 5xx and threw; a first-page
+          // failure stays a failure, but later pages keep what was read.
+          if (channels.length === 0) throw error;
+          return { channels, incomplete: SLACK_GENERIC_ERROR_MESSAGE };
+        }
 
         return channels.length > 0
           ? { channels, incomplete: message }
@@ -357,8 +365,12 @@ export const getSlackChannels = async (
       const body = await response.json().catch(() => null);
 
       for (const resource of body?.data ?? []) {
+        // Radix `Select.Item` refuses an empty value; one malformed resource
+        // would break the whole picker.
+        const channelId = resource?.id;
+        if (typeof channelId !== "string" || channelId.length === 0) continue;
         channels.push({
-          id: resource?.id,
+          id: channelId,
           name: resource?.attributes?.name ?? "",
           is_private: Boolean(resource?.attributes?.is_private),
         });

ui/app/(prowler)/integrations/slack/slack-page.integration.test.tsx

@@ -39,7 +39,19 @@ import {
 
 /** The shape the channel save is asserted against — only the id travels. */
 interface PatchIntegrationBody {
-  data: { attributes: { configuration: { channel_id: string } } };
+  data: PatchIntegrationData;
+}
+
+interface PatchIntegrationData {
+  attributes: PatchIntegrationAttributes;
+}
+
+interface PatchIntegrationAttributes {
+  configuration: PatchChannelConfiguration;
+}
+
+interface PatchChannelConfiguration {
+  channel_id: string;
 }
 
 /** The workspace the fixtures connect. */