Setup wizard: plugin display names + GE-Enforce next-steps pointer

Plugins list now carries a displayname (manifest display_name, else the
machine name title-cased). Adds display_name to the four whose title-case
was wrong: GE-Enforce, USB, Measuring Tools, Knowledge Base. The setup
wizard Features step and Settings > Plugins render it, so "Geenforce"/"Usb"
are gone.

Finish step shows a pointer when GE-Enforce is enabled: it still needs a
scoped service token (Settings > API Tokens) and a share export root
(GE-Enforce page) before the fleet uses it - operational config the wizard
does not collect.

frontend build green; naming green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/views/settings/PluginsList.vue

@@ -24,7 +24,7 @@
             </thead>
             <tbody>
               <tr v-for="p in plugins" :key="p.name">
-                <td>{{ p.name }}</td>
+                <td>{{ p.displayname || p.name }}</td>
                 <td class="mono">{{ p.version }}</td>
                 <td class="cell-truncate" :title="p.description">{{ p.description || '-' }}</td>
                 <td>