feat(FN-4174): complete Step 6 — apply locked-source disabled styling

Fusion-Task-Id: FN-4174
Fusion-Task-Lineage: 8b50a52b-dc3a-448d-998b-09023fbdd9af

packages/dashboard/app/components/SettingsModal.css

@@ -402,6 +402,15 @@
   background: var(--text-muted);
 }
 
+.settings-research-source-locked {
+  cursor: default;
+  color: var(--text-muted) !important;
+}
+
+.settings-research-source-locked input[type="checkbox"] {
+  cursor: not-allowed;
+}
+
 .settings-research-source-grid {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));

packages/dashboard/app/components/SettingsModal.tsx

@@ -4528,7 +4528,10 @@ export function SettingsModal({
             </div>
             <div className="form-group">
               <label>Enabled Sources</label>
-              <label htmlFor="research-project-source-webSearch" className="checkbox-label">
+              <label
+                htmlFor="research-project-source-webSearch"
+                className="checkbox-label settings-research-source-locked"
+              >
                 <input id="research-project-source-webSearch" type="checkbox" checked disabled readOnly />
                 Web Search <span className="settings-muted">Always on</span>
               </label>