Show how much storage space is used by shared files

Requires at least https://hg.prosody.im/prosody-modules/rev/883ad8b0a7c0

snikket_web/admin.py

@@ -682,6 +682,11 @@ async def system() -> typing.Union[str, quart.Response]:
         except KeyError:
             pass
 
+        try:
+            metrics["prosody_uploads"] = prosody_metrics["uploads"]
+        except KeyError:
+            pass
+
         for k in list(metrics.keys()):
             if metrics[k] is None:
                 # so that defaulting in jinja works

snikket_web/templates/admin_system.html

@@ -68,6 +68,14 @@
 			<em>{% trans %}unknown{% endtrans %}</em>
 			{%- endif -%}
 		</dd>
+		<dt>{% trans %}Storage used by shared files{% endtrans %}</dt>
+		<dd>
+			{%- if metrics.prosody_uploads -%}
+			{{ metrics.prosody_uploads | format_bytes }}
+			{%- else -%}
+			<em>{% trans %}unknown{% endtrans %}</em>
+			{%- endif -%}
+		</dd>
 		<dt>{% trans %}Connected devices{% endtrans %}</dt>
 		<dd>
 			{%- if metrics.prosody_devices | default(None) is not none -%}