update project structure

- move agent to /agent
- change /beszel to /src
- update workflows and docker builds

src/common/common-ssh.go

@@ -0,0 +1,10 @@
+package common
+
+var (
+	// Allowed ssh key exchanges
+	DefaultKeyExchanges = []string{"curve25519-sha256"}
+	// Allowed ssh macs
+	DefaultMACs = []string{"hmac-sha2-256-etm@openssh.com"}
+	// Allowed ssh ciphers
+	DefaultCiphers = []string{"chacha20-poly1305@openssh.com"}
+)