feat(server): implement sealed share lifecycle

Signed-off-by: JustMe <mr.toing@outlook.com>

server/src/WebDrop.Core/Enums.cs

@@ -0,0 +1,53 @@
+using System.Text.Json.Serialization;
+
+namespace WebDrop.Core;
+
+[JsonConverter(typeof(JsonStringEnumConverter<ChannelMode>))]
+public enum ChannelMode : byte
+{
+    [JsonStringEnumMemberName("enc")] Enc = 1,
+    [JsonStringEnumMemberName("raw")] Raw = 2,
+}
+
+[JsonConverter(typeof(JsonStringEnumConverter<DeletePolicy>))]
+public enum DeletePolicy : byte
+{
+    [JsonStringEnumMemberName("owner_only")] OwnerOnly = 0,
+    [JsonStringEnumMemberName("own")] Own = 1,
+    [JsonStringEnumMemberName("anyone")] Anyone = 2,
+}
+
+/// <summary>请求声明并通过验证的角色,数值越大权限越高。</summary>
+public enum Role : byte
+{
+    None = 0,
+    Read = 1,
+    Write = 2,
+    Owner = 3,
+}
+
+[Flags]
+public enum FrameFlags : byte
+{
+    None = 0,
+    Final = 1,
+    Snapshot = 2,
+    Gated = 4,
+    Enc = 8,
+}
+
+public enum LogKind : byte
+{
+    Frame = 1,
+    Tombstone = 2,
+    Announce = 3,
+}
+
+public enum TombstoneReason : byte
+{
+    Deleted = 0,
+    Expired = 1,
+    Evicted = 2,
+    DownloadLimit = 3,
+    Superseded = 4,
+}