app/matrix: enable wal=logical for postgres, add tmp mount

This is quite hacky, but we intend to remove that postgres soon anyway.
The changes to synapse's resource limits are to reflect current state of
prod.

Change-Id: Ic7beaa3e7ee378c0e10ba24f9a5a3aee67c2ccf2
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1468
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/app/matrix/lib/matrix-ng.libsonnet b/app/matrix/lib/matrix-ng.libsonnet
index ac895bc..91c92d2 100644
--- a/app/matrix/lib/matrix-ng.libsonnet
+++ b/app/matrix/lib/matrix-ng.libsonnet
@@ -242,6 +242,7 @@
             opts: {
                 max_connections: "300",
                 shared_buffers: "80MB",
+                wal_level: "logical",
             },
         },
     },