style(frontend) : apply UI corrections from design review

- Page titles in blue primary (#222783)
- Double main content margins (px-16 py-24)
- Remove blue border above sidebar timer
- Remove project color dot, use project color on title text
- All delete buttons/icons orange (#E2953C)
- Fix collapsed sidebar logo (object-cover object-left)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/components/ui/DataTable.vue

@@ -34,7 +34,7 @@
                     </td>
                     <td v-if="deletable" class="px-4 py-3">
                         <button
-                            class="text-red-500 hover:text-red-700"
+                            class="text-[#E2953C] hover:text-[#c97a2f]"
                             @click.stop="$emit('delete', item)"
                         >
                             <Icon name="mdi:delete-outline" size="20" />