feat!: genesis-pinned operator set, server identity with an encrypted control link, key-less join codes; release key continuity

Join codes need no passkey touch and carry only public values (genesis
fingerprint, owner credentials, installer hashes). Nodes pin the genesis and
owners at enrollment and only follow passkey-signed operator set versions.
The panel's server key is listed in the set; pinned nodes require its
signature and run the control link under AES-256-GCM. Password sessions carry
no capabilities. The updater adopts a next_key from a signed manifest.

Bump version to 0.2.0. [CI SKIP]

backend/src/MoShiro.Backend.Application/Models/AgentModels.cs

@@ -30,8 +30,7 @@ public sealed record AgentRecord(
     bool Ipv6HostManual = false,
     IReadOnlyList<string>? ReportedAddresses = null,
     byte[]? TlsPublicKey = null,
-    string? AddedBy = null,
-    MemberProofDto? Proof = null);
+    string? AddedBy = null);
 
 /// <summary>管理员可以修改的字段（merge-patch 语义：为 null 的字段不改）。</summary>
 public sealed class AgentPatch
@@ -79,11 +78,10 @@ public sealed record JoinTokenInfo(
     long? RevokedAtMs,
     long CreatedAtMs,
     string Kind = "",
-    string? CreatedBy = null,
-    SignedStatementDto? Grant = null);
+    string? CreatedBy = null);
 
 /// <summary>
 /// <see cref="PublicKey"/> 是连 Backend 的身份公钥，<see cref="PeerPublicKey"/> 是对等面（连 Agent）的公钥，两把是节点自己生成的独立密钥；
 /// Agent 的 <c>peers</c> 里放的是后者。
 /// </summary>
-public sealed record ProbeRecord(string Id, string Name, byte[] PublicKey, long CreatedAtMs, long? RevokedAtMs, string? Ipv6DiagnosticsJson = null, byte[]? PeerPublicKey = null, string? AddedBy = null, MemberProofDto? Proof = null);
+public sealed record ProbeRecord(string Id, string Name, byte[] PublicKey, long CreatedAtMs, long? RevokedAtMs, string? Ipv6DiagnosticsJson = null, byte[]? PeerPublicKey = null, string? AddedBy = null);