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-server-2.yaml

@@ -1,6 +1,25 @@
-# STUB — not yet encrypted with sops.
-# Bootstrap:
-#   bash scripts/secrets/sync-host-keys.sh proxmox-ha-server-2
-#   sops updatekeys secrets/common.yaml  (allows ha-server-2 to decrypt shared secrets)
-#   sops secrets/ha-server-2.yaml        (create with: beszel-token)
-beszel-token: REPLACE
+beszel-token: ENC[AES256_GCM,data:0wooMaPiytDTGug=,iv:/WATBCEakrIvujt4oAeprw18W1n/WoK2zjpQdlVJl4Y=,tag:lhJa9hJgFqNFSB1Ogj5CtQ==,type:str]
+sops:
+    age:
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBhdmNmSFlmei9KbDRWU3lj
+            TVJoSW9FRE9sWUdBRkNIMTB3aVNERUp0U0c4CnZUUzIvYm1xL1JNMGFKcWlBK2xT
+            SCt4TTdlU0ZralArcUVFZEh1YTRQaWcKLS0tIEtKbnBZVlkrU2U3VzlycS9odXVi
+            VjhXeWtZdDhpTG12cUZwVDhKeWZPMmsKOtXLVB8Z0faO05BPCVQXBn8gbMOZeHxC
+            sHmt3vMWO0jrxM0WLql59VWAFsczNwb1fw89NdZMfd/XoVq2EUV8dA==
+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
+        - enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBucCtBR3N3Qm9JbTlLdTZT
+            eTlxWEsxUWZsUnMrWi9zSDdRVWZWejBUWFNVCnpyVEVLbTllVHg1a2RXRkVRZ05z
+            ZWlsSTBDWFF3bzkzaTFMVDQrVW1yczgKLS0tIFhKMll2OVdzWTcyeWdoaU85Vmla
+            WWEwRFgxNDF5czA3Q01LZ0NjY2toaTQKKawEiHUWss0NPuJng6UimekEOlxipiyC
+            ielJbLxma8WPLeLwBukFOBOTyNFxgsVBvwmBJ2k1iMIg1lCjhLD7RA==
+            -----END AGE ENCRYPTED FILE-----
+          recipient: age1scfc8p53q5aq2a87tcmsazmj8sfeft0s8kxg0et4nm3ucxyp3c3s6te82y
+    lastmodified: "2026-07-28T06:45:50Z"
+    mac: ENC[AES256_GCM,data:f50JYTzMJiEjB9+fNIs734CXrkN1IRgJKcoJ0GHoI5p75cfLfPxuzUifty9kQ/4DbM7LbWa5w+9occoV/yNOa86BKpPtU0LmlzXf904/SgOCUKhyHqhyO5mp8w71GoyLxx3ld8CbqfBu8t5l4gwbQamftsmQRxnUdU/Oa/CzdZQ=,iv:EewXBjeihw89h8ypH5u/G4YfoKZzkHqRWgSSIXU3/a0=,tag:lEWMvAkebMexDGGpE+wqkg==,type:str]
+    unencrypted_suffix: _unencrypted
+    version: 3.13.3