fix: add missing shire-zebra.ts.net DNS entries; update exodus Tailscale IP

genesis, zeke, linode, and exodus were missing shire-zebra.ts.net
aliases in the genesis dnsmasq hosts file. Only hosea, isaiah,
jeremiah, gitlab, matrix, chronicles, and nas1 had them. Since
genesis is the DNS server for the whole network, Prometheus (and
everything else) couldn't resolve those four hostnames, causing
instant connection failures on scrape.

Also update exodus Tailscale IP from 100.80.99.48 to 100.70.99.91
(stale IP in both network.json and the hosts file).

hosts/unstable/genesis/net/hosts

@@ -35,14 +35,14 @@
 # Tailscale hosts
 100.119.228.115 nas.home chronicles.shire-zebra.ts.net
 100.88.91.27 dns.home
-100.80.99.48 exodus.home
-100.96.198.104 genesis.home smart.home zwave.home nixcache.home gitcache.home dashy.home uptime.home speed.home
+100.70.99.91 exodus.home exodus.shire-zebra.ts.net
+100.96.198.104 genesis.home genesis.shire-zebra.ts.net smart.home zwave.home nixcache.home gitcache.home dashy.home uptime.home speed.home
 100.117.28.111 gitlab.home gitlab.shire-zebra.ts.net gitlab.thehellings.lan registry.thehellings.lan git.thehellings.lan
 100.68.203.1 hosea.home hosea.shire-zebra.ts.net grafana.home
 100.84.183.79 isaiah.home isaiah.shire-zebra.ts.net pgadmin.kubernetes longhorn.kubernetes
 100.102.186.39 jeremiah.home jeremiah.shire-zebra.ts.net matrix.kubernetes immich.kubernetes postgres.kubernetes
-100.90.74.19 zeke.home
-100.115.57.8 linode.home
+100.90.74.19 zeke.home zeke.shire-zebra.ts.net
+100.109.86.8 linode.home linode.shire-zebra.ts.net
 100.65.5.38 matrix.home matrix.shire-zebra.ts.net
 #100.127.55.22 jellyfin.home
 100.114.187.61 nas1.home nas1.shire-zebra.ts.net