feat: add Wireguard interface model

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

migrations/20250327112746_init.sql

@@ -0,0 +1,7 @@
+CREATE TABLE interfaces (
+    name TEXT PRIMARY KEY,
+    address INET NOT NULL,
+    port INTEGER NOT NULL CHECK (port > 0 AND port <= 65535),
+    private_key BYTEA NOT NULL,
+    default_network_netmask SMALLINT NOT NULL CHECK (default_network_netmask >= 0 AND default_network_netmask <= 32)
+);