nixos: Add working container VM (w/ vaultwarden)

Also improve IPv6 addressing / routing

secrets/user-passwd.txt.age

@@ -1,15 +1,16 @@
 age-encryption.org/v1
--> ssh-ed25519 SKXJUw HNKr/VHMm2Tm3zXJy/hiWFT/HwMrs5dzi+JSdfe/3wE
-NH/28Nkeij6o3h63Fu/h2dgI8b6spZ0dMKp/yUfTCq4
--> ssh-ed25519 B9K/XQ it45NurDEjYL5dAVJsJmi+MlIHKSpP2Lj7Fij5/ziUs
-1vKMO+h6aMAWDQDWwKrT0PwDhw90mk7x7uf27CCz27s
--> ssh-ed25519 LLxJog aAmssC1kqweHP1TEtkVurusq1AqIc8t7HZ7A7hjRtAw
-lDbexbeib25DPuFiObs+1PQgu1WPG8a/P01QD6tO1f8
--> X25519 lcKREBQdELTzOpxRXMJa5J9stI9u3tZJdAHGW2LC8W4
-7c+kF11czGa7DEq3+ZJW+iSLcU/XKn+YJlciQzLwP64
--> y251}dI-grease
-zIIT0zZ1oHhvxwQtUM6JsvhIqbQ0fRz5YFJMrxkwk8FDwgIyoKHQhVWNYmFDWhEs
-K0QD0scV1HUGGAJdMoePqHw
---- a2PYkwWrS0NFhoL/0IgmuvKRjkORQrotG+RKXVtXeiI
-t<>6<EFBFBD><36>!<21>,ޟo.<2E>n<EFBFBD>7J<02><>K`<60><1D>a<EFBFBD>i.<05><>c<EFBFBD>>$<>W<EFBFBD><57>>"8<03><><r4Y'{<7B><><EFBFBD>O"B<><42><EFBFBD><06>yg
-P&<26>
+-> ssh-ed25519 SKXJUw WuE37itEkLwXXidFy5KSirx2nHJrMSv2s1QtdWX8SFQ
++hQkpae7pD8CddccW/EkXdM9PwLvR9ExhfiMSpDrmR4
+-> ssh-ed25519 B9K/XQ dcFFZZW7YmoIE9t4f5q75Fiydok4dlFvMhUe4AL0glo
+VNmnLMMyPMmeaRS9TCve0jFLoOsMOjFinERzbCYb5VU
+-> ssh-ed25519 b6YMqg rzXuWZ70pstFv91Pc9rEzX6zQoP7EzFbaVqLztzeDEg
+FfdsqfWrWhVp69Y06kMdJLki4SZcsTfQgpGkOV8OEWY
+-> ssh-ed25519 Lqn0Yw w34t0WrHrI0X9YPiKuqtA/g4nb5u+MUR5IMhxax94GA
+om8lmlCa7b5dFTHgTWkfG0JQlo7SGuOsMKWV+ZyZODo
+-> X25519 /D+YDNaHuzjd1qfUVGSzMv/Gme3c7EfnAReZwijNrHU
+Mq8c561BFjPNpevYYxZoQlXyukWoJ/FqHMygRVIa8L4
+-> K#M-grease
+cqBqOMKVvx0kDafiKK3izbQO2jJWDt0cw1z7iIlO2HQcDyrymtIkwiUcZ0DnjCO8
+0GP/yJXOxwzP/L7+
+--- 9euRtnfRLtKp2uI4YFGFJNNIvn8+YtQ8Ugoki23oSAQ
+<EFBFBD>