Add the shared packages for the sharks stack

model, tunnel, wg, authtoken, netguard, docker and dotenv, split out of the
original single repository so Hammerhead, Blacktip and Bamboo can live in
their own repos and import them. README extended; LICENSE unchanged.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

go.mod

@@ -0,0 +1,18 @@
+module git.veillax.com/Veillax/reef
+
+go 1.27.3
+
+require (
+	github.com/Microsoft/go-winio v0.6.4
+	golang.zx2c4.com/wireguard v0.0.0-20261024220952-b3bc704ef0ee
+)
+
+require (
+	github.com/google/btree v1.1.2 // indirect
+	golang.org/x/crypto v0.58.0 // indirect
+	golang.org/x/net v0.61.0 // indirect
+	golang.org/x/sys v0.49.0 // indirect
+	golang.org/x/time v0.7.0 // indirect
+	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 // indirect
+	gvisor.dev/gvisor v0.0.0-20250503011706-39ed1f5ac29c // indirect
+)