Let API clients resolve user ids to names (#1894)

Archives, the queue and statistics report ownership as a numeric
created_by_id, and statistics accept it as a filter, but nothing let an
API key discover whose id was whose -- the only user listing returns
emails, roles, group membership and full permission sets, so it is
administrative and rejects keys.

Add GET /users/slim returning id + username only, gated on a new
users:read_slim permission mapped to can_read_status. That grants no
data a key could not already reach: for API-keyed requests the
permission deps return None as current_user, so the stats:filter_by_user
guard short-circuits and ?created_by_id=N is already honoured for every
N. What was missing was the ability to address the filter, not
permission to use it. The full listing stays unmapped = admin-only.

Also fix /auth/me, which answered an API key with a synthetic
administrator: id 0, role admin, is_admin true and every permission in
the enum. A key cannot reach an administrative route at all, so clients
building their UI from that response rendered actions that 403 on use.
It now reports the key owner's identity, is_admin false, and the
permissions the key's scopes actually admit. Ownerless legacy keys keep
id 0 but no longer claim admin.

---

Source user names from the slim listing where only names are needed (#1894)

Stats filter-by-user, the Archives print log filter, the File Manager
username autocomplete, the camera-token owner column and the Finance
member picker all render nothing but a username, but all of them read
the full user listing, which is gated on the admin-level users:read.
An operator granted stats:filter_by_user but not users:read got an
empty filter with no indication why.

Point them at /users/slim under a separate react-query key, since the
full listing shares the 'users' key and the two shapes would clobber
each other in the cache.

static/index.html

@@ -26,7 +26,7 @@
 
     <!-- Splash screens for iOS -->
     <link rel="apple-touch-startup-image" href="/img/android-chrome-512x512.png" />
-    <script type="module" crossorigin src="/assets/index-Bh7umAlT.js"></script>
+    <script type="module" crossorigin src="/assets/index-DjNRlhiN.js"></script>
     <link rel="stylesheet" crossorigin href="/assets/index-jOkuIvep.css">
   </head>
   <body>