feat: rewrite database schema for localized autoproxy

PluralKit.Core/Database/Repository/ModelRepository.Autoproxy.cs

@@ -0,0 +1,35 @@
+using Dapper;
+
+using SqlKata;
+
+namespace PluralKit.Core;
+
+public partial class ModelRepository
+{
+    public async Task UpdateAutoproxy(SystemId system, ulong? guildId, ulong? channelId, AutoproxyPatch patch)
+    {
+        var locationStr = guildId != null ? "guild" : (channelId != null ? "channel" : "global");
+        _logger.Information("Updated autoproxy for {SystemId} in location {location}: {@AutoproxyPatch}", system, locationStr, patch);
+
+        var query = patch.Apply(new Query("autoproxy")
+            .Where("system", system)
+            .Where("guild_id", guildId ?? 0)
+            .Where("channel_id", channelId ?? 0)
+        );
+        _ = _dispatch.Dispatch(system, guildId, channelId, patch);
+        await _db.ExecuteQuery(query);
+    }
+
+    // todo: this might break with differently scoped autoproxy
+    public async Task<AutoproxySettings> GetAutoproxySettings(SystemId system, ulong? guildId, ulong? channelId)
+        => await _db.QueryFirst<AutoproxySettings>(new Query("autoproxy").AsInsert(new {
+            system = system,
+            guild_id = guildId ?? 0,
+            channel_id = channelId ?? 0,
+        })
+            .Where("system", system)
+            .Where("guild_id", guildId ?? 0)
+            .Where("channel_id", channelId ?? 0),
+            "on conflict (system, guild_id, channel_id) do update set system = $1 returning *"
+        );
+}