feat(ha): implement clan vars and fully encrypt all HA secrets

- Run sync-host-keys.sh for proxmox-ha-server-{1,2}: generates SSH host
  key pairs in vars/per-machine/, registers age anchors in .sops.yaml,
  adds both hosts as recipients for common.yaml, ha-corosync-authkey,
  and per-host secrets/keytab files
- Re-encrypt secrets/common.yaml with both new host keys
- Convert all stub secrets to real sops-encrypted files:
    secrets/ha-server-{1,2}.yaml    (YAML, beszel-token = PLACEHOLDER)
    secrets/ha-server-{1,2}.keytab  (binary, stub text encrypted)
    secrets/ha-corosync-authkey      (binary, stub text encrypted)
- Add scripts/ha/deploy.sh: full lifecycle script (bridge setup, VM
  creation, DRBD disk + storage NIC attachment, boot wait, cluster-init,
  acceptance tests, --destroy)

Bootstrap order (operator runs these before first deploy):
  1. bash scripts/ha/deploy.sh            # deploys, tests
  # Post-deploy secret replacement:
  2. sops secrets/ha-server-{1,2}.yaml   (set real beszel-token)
  3. bash scripts/ipa/create-nixos-ipa-host-account.sh --ip 192.168.2.228 ha-server-1
  4. bash scripts/ipa/create-nixos-ipa-host-account.sh --ip 192.168.2.227 ha-server-2
  5. Set services.beszel.agent.environment.KEY in host.nix after hub pairing
  6. nixos-rebuild switch on both nodes to pick up real secrets

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HaH1cSGvhogRP5ExoF6nD8

secrets/ha-corosync-authkey

@@ -1 +1,22 @@
-STUB: run cluster-init.sh to generate, then: sops -e --input-type binary /etc/corosync/authkey > secrets/ha-corosync-authkey
+{
+	"data": "ENC[AES256_GCM,data:olqZm/3yxtVnlDeYzAWnXjUP9pgkruFEpeS6qONHSfdrj0lJOch44zn1pbG6Jg5QYcksny0rHki9PJEZSbRIyrZ2mSKfTJing3n9M5ODm9xPMbNYn8cpVB4AzZmCSAH7mN4p/98+5hJ1qzopGwCgKTcOOJ9DMUl9AStXORY=,iv:R2K3OehIfyKZXRFH3Y9KYnvEp6CjHPT4Ki2P1YrC6+I=,tag:1FM/E0n9teARAZ1HZM4b3A==,type:str]",
+	"sops": {
+		"age": [
+			{
+				"enc": "-----BEGIN AGE ENCRYPTED FILE-----\nYWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSA3RFRoRW1rRklxbXYybUtu\nL1lEOXJBMDNCN1paU1k5N0hQRTJYQ1dQcTBVCk9OYnloOFZad2toOHo0UXFYSzNR\nZDUwV00vKzVnckMwSE9MMnE4RUozZTgKLS0tIFByL3Z3SzJFeEVNZjhuRDNTMzFo\nNU5tZ2tQU1ZORE5qNm1JUEJrTGdzUHMKypYeJz6BeUUY4aPKazB1nxncOA3DGkal\nfemLr9uwCJw+D3xfXzrIKrI0w3OH7bu2LmWqrNDSz3Bwa5VDuHoLqQ==\n-----END AGE ENCRYPTED FILE-----\n",
+				"recipient": "age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad"
+			},
+			{
+				"enc": "-----BEGIN AGE ENCRYPTED FILE-----\nYWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBqTzhtOHM1Q1lWRXdadHB6\nZ1VrMXFsQWZEbDBMMnQvYnZSN090VnpyQnd3CkdJaHBsbzQ4SERmU0dBS2RZMUpi\nZVYrZmtSNXhiaDNTZkNMVEZud3ZzT3cKLS0tIFhETER5eWJRK05ValFhenRnSGg1\nc1prdWVTVmMyWWt2UkNXWVRLcWRHcm8KjVn1faGmsWiFzcNg4PnxZQfeQONFKz/i\nyJGJc7w2KSZ3La+44jfitMziJQ3AFRUlAhGDX25kWZJ7PtjmFvYwuQ==\n-----END AGE ENCRYPTED FILE-----\n",
+				"recipient": "age1nxlnrevqs2msdatze562vz6ym4pgydt2zndye83lwqauy6flggtqrevyw5"
+			},
+			{
+				"enc": "-----BEGIN AGE ENCRYPTED FILE-----\nYWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBkVXFQazlvUEx2NzVUNlF1\nN3FQNTdFL1FtSDhCdmNQclRMdG1vRVhvcEhzClF4Ykh1ZS9JekFzOHkvOVphejVy\nd2s0a0IrZ1d4V3diOGNvMlBHUVlwTmMKLS0tIEFhTE13Q2F1di9ESXdJVDhJUVl4\na1kzNDBLcHhlRGg2Y3hSSmdEc2k5MlEKpU2sIv5Pq0LaKkvqA/fRkiB9PcvsSjvq\no4iEFzGNDi63QzXqftWnzengEy/6nWGNA31fzScQftESesGlKfYYlA==\n-----END AGE ENCRYPTED FILE-----\n",
+				"recipient": "age1scfc8p53q5aq2a87tcmsazmj8sfeft0s8kxg0et4nm3ucxyp3c3s6te82y"
+			}
+		],
+		"lastmodified": "2026-07-28T06:46:00Z",
+		"mac": "ENC[AES256_GCM,data:xJHyh4JuY+qnKljS3mtfN4Cy0pGPUszhU4ud2L8JxTFGUHTXhZzwQ3s1vM88efLTwM7yDK7oBMBUH2xligAzglDnqkE1T0l7R9k+hyldm4nYqOK6Y8GyPt/aald6oLYGCx3J7Ap0Oqq/crU+s4NiY9enf+R+08jliFyrPBHuRSY=,iv:FGtURIfSrf1tRGqpPfn40GqybhNYFBcvR7n1YkcAMGY=,tag:ir0TU7YuxpPuew+nyC9/eg==,type:str]",
+		"version": "3.13.3"
+	}
+}