feat(grfn/mugwump): Set up agenix

Start setting up agenix with secrets in //users/grfn/secrets for
mugwump, starting with my cloudflare API key which I use for the ddns
from my home apartment

Change-Id: Ida66cb91da3415357a512039d6c23402f0ae9388
Reviewed-on: https://cl.tvl.fyi/c/depot/+/4683
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI

users/grfn/secrets/.envrc

@@ -0,0 +1 @@
+eval "$(lorri direnv)"

users/grfn/secrets/cloudflare.age

@@ -0,0 +1,9 @@
+age-encryption.org/v1
+-> ssh-ed25519 CpJBgQ w4W+pzmVIEMF0uZN7KZMAppJaLjEeDKoe7i9LGayKDQ
+Rd8k+3csmbZQIrp09ZUfCAOZVwI0BZ6hCBN3nkZQMp4
+-> ssh-ed25519 LfBFbQ dyv1splvcftMd1zWDkPBfsgvXxH5neZlO7ZjrhyzNHI
+N/kqc/luOl8lsZcbaxF8/3ULsL78zvZhkiCarohe+G4
+-> \w7t-grease lo&b JZpCA
+nN2lH0W9+zulMjZMLPMk61+xsrQ
+--- voTpUbu8OiJQyuKB7tIOvlErgY0jg2w7N3MehD5FIdM
+&cŽz“læ	Î|Kœ<4B>M<EFBFBD>~<7E>®2àe¢ºÐ
¨°
úUN8“Pâ~}Ý*ÇhÞÁêSYJJÇØÁFÉŠâoºÂc=ˆL<CB86>û­`z«“ŽO7€ùòËK—ÖgZ”ÝÛÕ¿.ÎaXDÚHЦ€ýÙ8„7½ÙÉÌþã–ó8

users/grfn/secrets/default.nix

@@ -0,0 +1,2 @@
+{ depot, ... }:
+depot.ops.secrets.mkSecrets ./. (import ./secrets.nix)

users/grfn/secrets/secrets.nix

@@ -0,0 +1,8 @@
+let
+  grfn = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIMcBGBoWd5pPIIQQP52rcFOQN3wAY0J/+K2fuU6SffjA";
+  mugwump = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFE2fxPgWO+zeQoLBTgsgxP7Vg7QNHlrQ+Rb3fHFTomB";
+in
+
+{
+  "cloudflare.age".publicKeys = [ grfn mugwump ];
+}

users/grfn/secrets/shell.nix

@@ -0,0 +1,8 @@
+let
+  depot = import ../../.. {};
+in
+depot.third_party.nixpkgs.mkShell {
+  buildInputs = [
+    depot.third_party.agenix.cli
+  ];
+}