🔒 fix: Enforce admin-only column visibility in logs tables

Ensure non-admin users cannot enable columns reserved for administrators
across the following hooks:

* web/src/hooks/usage-logs/useUsageLogsData.js
  - Force-hide CHANNEL, USERNAME and RETRY columns for non-admins.

* web/src/hooks/mj-logs/useMjLogsData.js
  - Force-hide CHANNEL and SUBMIT_RESULT columns for non-admins.

* web/src/hooks/task-logs/useTaskLogsData.js
  - Force-hide CHANNEL column for non-admins.

The checks run when loading column preferences from localStorage, overriding
any tampered settings to keep sensitive information hidden from
unauthorized users.

web/src/hooks/mj-logs/useMjLogsData.js

@@ -94,6 +94,11 @@ export const useMjLogsData = () => {
         const parsed = JSON.parse(savedColumns);
         const defaults = getDefaultColumnVisibility();
         const merged = { ...defaults, ...parsed };
+        // If not admin, force hide columns only visible to admins
+        if (!isAdminUser) {
+          merged[COLUMN_KEYS.CHANNEL] = false;
+          merged[COLUMN_KEYS.SUBMIT_RESULT] = false;
+        }
         setVisibleColumns(merged);
       } catch (e) {
         console.error('Failed to parse saved column preferences', e);

web/src/hooks/task-logs/useTaskLogsData.js

@@ -92,6 +92,10 @@ export const useTaskLogsData = () => {
         const parsed = JSON.parse(savedColumns);
         const defaults = getDefaultColumnVisibility();
         const merged = { ...defaults, ...parsed };
+        // If not admin, force hide columns only visible to admins
+        if (!isAdminUser) {
+          merged[COLUMN_KEYS.CHANNEL] = false;
+        }
         setVisibleColumns(merged);
       } catch (e) {
         console.error('Failed to parse saved column preferences', e);

web/src/hooks/usage-logs/useUsageLogsData.js

@@ -116,6 +116,12 @@ export const useLogsData = () => {
         const parsed = JSON.parse(savedColumns);
         const defaults = getDefaultColumnVisibility();
         const merged = { ...defaults, ...parsed };
+        // If not admin, force hide columns only visible to admins
+        if (!isAdminUser) {
+          merged[COLUMN_KEYS.CHANNEL] = false;
+          merged[COLUMN_KEYS.USERNAME] = false;
+          merged[COLUMN_KEYS.RETRY] = false;
+        }
         setVisibleColumns(merged);
       } catch (e) {
         console.error('Failed to parse saved column preferences', e);