fix: correct 2023-03-21 client wire contracts across the API and notify surfaces

Audits every route the March-2023 client can call against what this server
actually serves, and fixes the defects that were breaking gameplay. Adds
docs/recroom-2023-client-api-complete.md as the reference: ~500 route
literals across 13 subsystems, with verb, request/response shape, and a
per-subsystem diff. 315 defects catalogued; the ones fixed here are listed
in its "Already fixed" table.

Path coverage was never the problem — 465 of 506 routes already had
handlers. The failures were in shape, and they cluster into four causes:

- Wrong verb. The verb is a BestHTTP.HTTPMethods ordinal (GET=0 .. PATCH=5),
  confirmed from that enum's static constructor. Routes registered POST-only
  while the client PUTs returned 405, which made room consumables neither
  buyable nor consumable and blocked every room-key edit.
- Bare scalar wrapped in an object. The client reads `1000`, not
  `{"Limit":1000}`; the issuing method signature says which. Wrapping makes
  the deserializer throw and the feature dies silently.
- [FromBody] vs form-urlencoded. The client sends nearly every write as form
  data, which an [ApiController] action bound [FromBody] rejects with 415
  before the handler runs. This alone broke all 13 club member-management
  endpoints. Adds Binding/FormOrJsonModelBinder so this is fixed once.
- Notify dispatch keys. Both enum overloads of the client's RegisterHandler
  lower the id via Int32.ToString() and register only that numeric key, and
  lookup is a case-sensitive TryGetValue that returns silently on a miss. We
  were sending the enum NAME for most ids, so friend-request updates, forced
  logout, maintenance broadcasts, live balance and consumable updates, and
  invention moderation pushes all evaporated with no error anywhere.

Notable behavioural bugs fixed:

- Editing a club announcement deleted it: PUT was a third binding on the
  delete handler. Split apart, and the missing create route added.
- leaderboard/CheckAndSetStat did not exist. The 2023 client has no SetStat
  literal at all, so every leaderboard score it wrote was discarded.
- Setting a club clubhouse cleared it: the handler read roomId from the query
  while the client sends it in the body, then wrote the resulting null.
- Club join requests were inverted (the enum is Open=0, InviteOnly=1,
  AskToJoin=2), so ask-to-join clubs rejected everyone and invite-only clubs
  quietly admitted them.
- Room bans were pushed as id 24, for which the client registers no handler;
  they now go out as ModerationKick with IsBan, so the ban takes effect
  immediately instead of at next login.
- Room-key ownership queries answered for the wrong player, and "has anyone
  bought this key" asked "did I buy it" — always false for the creator.

Also persists settings that were previously acknowledged and dropped
(playlist accessibility/restrictions/level-voting/warning, per-player status
visibility, VR movement mode and avoid-juniors, custom room codes), which is
what the new columns in the migration are for.

One test asserted the old nested PriceAndCurrency response shape; the
client's consumable formatter has no such key and reads Price and
PurchaseCurrencyId flat, so the test was corrected alongside the handler.

DorkNet.Server/Controllers/API/ExternalFriendInvite/ExternalFriendInviteController.cs

@@ -43,37 +43,43 @@ public class ExternalFriendInviteController(DorkNetDbContext db) : ControllerBas
         return Ok(new { Success = true, InviteCode = code, PhoneNumber = phoneNumber ?? string.Empty });
     }
 
+    /// <summary>Accounts who joined via this player's platform invites.
+    ///
+    /// The response is a bare array of account ids — the issuing method is
+    /// <c>FGLDKEJLAKB&lt;List&lt;System.Int32&gt;&gt; POJMMCCLNCB()</c>
+    /// (RecNet.Runtime/OMHDDLFIPLP.txt:923). Returning objects
+    /// (<c>{InviteCode, Kind, Value, CreatedAt}</c>) made Json.NET throw as soon
+    /// as any referrer existed, so the referral screen broke for exactly the
+    /// players who had referred someone.</summary>
     [HttpGet("api/externalfriendinvite/v1/getplatformreferrers")]
     [HttpPost("api/externalfriendinvite/v1/getplatformreferrers")]
     public async Task<IActionResult> GetPlatformReferrers()
-    {
-        var rows = await db.PlayerSettings
-            .Where(s => s.PlayerId == Me && s.Key.StartsWith("externalinvite:platform:"))
-            .OrderByDescending(s => s.Id)
-            .ToListAsync();
-        return Ok(rows.Select(ToInviteWire));
-    }
+        => Ok(await ReferrerIdsAsync("externalinvite:platform:"));
 
+    /// <summary>Same bare-id-array contract as
+    /// <see cref="GetPlatformReferrers"/>, for text-message invites.</summary>
     [HttpGet("api/externalfriendinvite/v1/gettextmessagereferrers")]
     [HttpPost("api/externalfriendinvite/v1/gettextmessagereferrers")]
     public async Task<IActionResult> GetTextMessageReferrers()
+        => Ok(await ReferrerIdsAsync("externalinvite:text:"));
+
+    /// <summary>Account ids recorded against the caller's invites of the given
+    /// kind. The redeeming account id is stored as the second pipe-delimited
+    /// field once an invite is claimed; unclaimed invites contribute nothing.</summary>
+    private async Task<List<int>> ReferrerIdsAsync(string keyPrefix)
     {
         var rows = await db.PlayerSettings
-            .Where(s => s.PlayerId == Me && s.Key.StartsWith("externalinvite:text:"))
+            .Where(s => s.PlayerId == Me && s.Key.StartsWith(keyPrefix))
             .OrderByDescending(s => s.Id)
+            .Select(s => s.Value)
             .ToListAsync();
-        return Ok(rows.Select(ToInviteWire));
+
+        return rows
+            .Select(v => v.Split('|'))
+            .Select(parts => int.TryParse(parts.ElementAtOrDefault(1), out var id) ? id : 0)
+            .Where(id => id > 0)
+            .Distinct()
+            .ToList();
     }
 
-    private static object ToInviteWire(PlayerSettingEntity row)
-    {
-        var parts = row.Value.Split('|');
-        return new
-        {
-            InviteCode = row.Key.Split(':').Last(),
-            Kind = row.Key.Contains(":text:") ? "text" : "platform",
-            Value = parts.FirstOrDefault() ?? string.Empty,
-            CreatedAt = parts.LastOrDefault() ?? string.Empty,
-        };
-    }
 }