receipts: Deploy Receipts management tool

This is a custom-built application for managing purchase receipts.  It
integrates with Firefly III to fill some of the gaps that `xactmon`
cannot handle, such as restaurant bills with tips, gas station
purchases, purchases with the HSA debit card, refunds, and deposits.

Photos of receipts can be taken directly within the application using
the User Media Web API, or uploaded as existing files.  Each photo is
associated with transaction data, including date, vendor, amount, and
general notes.  These data are also synchronized with Firefly whenever
possible.

receipts/postgres-cert.yaml

@@ -0,0 +1,12 @@
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  name: postgres-client-cert
+spec:
+  commonName: receipts
+  privateKey:
+    algorithm: ECDSA
+  secretName: postgres-client-cert
+  issuerRef:
+    name: postgresql-ca
+    kind: ClusterIssuer