Add application support teams with contacts

Replaces the legacy supportteams/appowners pair: supportteams
(teamname unique, teamurl ServiceNow link) + supportteamcontacts
(multiple named contacts with SSO per team, the people you reach out
to), applications.supportteamid intact. Migration 7d18 migrates each
legacy team owner into a contact, drops appowners, and has a validated
downgrade. New /api/supportteams CRUD (admin writes, import-mode
timestamps, teamname lookup), Support card on application detail,
contacts column on the list, and a settings management page.
IMPORT-API.md mapping updated to the concrete endpoints.

658 tests pass; live dev migration applied (24 teams / 24 contacts);
fresh-install and downgrade round-trips verified on scratch DBs.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/views/applications/ApplicationsList.vue

@@ -34,7 +34,7 @@
                 <th>Application Name</th>
                 <th>Description</th>
                 <th>Support Team</th>
-                <th>App Owner</th>
+                <th>Contacts</th>
                 <th>Actions</th>
               </tr>
             </thead>
@@ -64,8 +64,8 @@
                   </span>
                 </td>
                 <td class="description">{{ app.appdescription || '-' }}</td>
-                <td>{{ app.supportteam?.teamname || '-' }}</td>
-                <td>{{ app.supportteam?.owner?.appowner || '-' }}</td>
+                <td>{{ app.supportteamname || '-' }}</td>
+                <td>{{ app.contacts && app.contacts.length ? app.contacts.map(c => c.name).join(', ') : '-' }}</td>
                 <td class="actions">
                   <router-link
                     :to="`/applications/${app.appid}`"