feat: import leftover student fields into notes and show them on the roster

Store leftover CSV columns on hidden student notes, move catalog import to /events/import, and persist Students index columns from Chapter Settings.

Co-authored-by: Cursor <cursoragent@cursor.com>

WebApp/Services/ChapterSettingsWriter.cs

@@ -1,4 +1,5 @@
 using System.Text.Json;
+using System.Text.Json.Nodes;
 using WebApp.Models;
 
 namespace WebApp.Services;
@@ -8,6 +9,11 @@ namespace WebApp.Services;
 /// </summary>
 public class ChapterSettingsWriter : IChapterSettingsWriter
 {
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        WriteIndented = true
+    };
+
     private readonly IWebHostEnvironment _environment;
     private readonly IConfiguration _configuration;
     private readonly ILogger<ChapterSettingsWriter> _logger;
@@ -29,35 +35,41 @@ public class ChapterSettingsWriter : IChapterSettingsWriter
         var appSettingsPath = GetAppSettingsPath();
         var dataDir = Path.GetDirectoryName(appSettingsPath);
         if (dataDir != null && !Directory.Exists(dataDir))
-        {
             Directory.CreateDirectory(dataDir);
-        }
 
-        Dictionary<string, object?> root;
+        JsonObject root;
         if (File.Exists(appSettingsPath))
         {
             var existingJson = await File.ReadAllTextAsync(appSettingsPath, cancellationToken);
-            root = JsonSerializer.Deserialize<Dictionary<string, object?>>(existingJson)
-                   ?? [];
+            root = JsonNode.Parse(existingJson) as JsonObject ?? [];
         }
         else
         {
             root = [];
         }
 
-        root["ChapterSettings"] = settings;
+        var incoming = JsonSerializer.SerializeToNode(settings, JsonOptions) as JsonObject ?? [];
+        if (root["ChapterSettings"] is JsonObject existing)
+        {
+            foreach (var property in incoming)
+                existing[property.Key] = property.Value?.DeepClone();
+        }
+        else
+        {
+            root["ChapterSettings"] = incoming;
+        }
 
-        var options = new JsonSerializerOptions { WriteIndented = true };
-        var json = JsonSerializer.Serialize(root, options);
-        await File.WriteAllTextAsync(appSettingsPath, json, cancellationToken);
+        await File.WriteAllTextAsync(appSettingsPath, root.ToJsonString(JsonOptions), cancellationToken);
+
+        if (_configuration is IConfigurationRoot configurationRoot)
+            configurationRoot.Reload();
 
         _logger.LogInformation("Chapter settings written to {Path}", appSettingsPath);
     }
 
     public async Task UpdateCompetitionYearAsync(string competitionYear, CancellationToken cancellationToken = default)
     {
-        var settings = _configuration.GetSection("ChapterSettings").Get<ChapterSettings>()
-                       ?? new ChapterSettings();
+        var settings = ChapterSettings.FromConfiguration(_configuration);
         settings.CompetitionYear = competitionYear;
         await WriteAsync(settings, cancellationToken);
     }