Import march-2020-03-10 from private repo (scrubbed 2026-05-27)

Targets Rec Room 2020.03.10 client (also serves 2020.03.06).

Re-import after adding:
- DorkNet.ClientMod/dorknet-clientmod.json.template — config schema
  the launcher's manifest-driven patcher renders into UserData/.
- tools/build-patcher-zip.ps1 — produces dorknet-clientpatch-{key}.zip
  for v1-march-* Release uploads.
- .github/workflows/release.yml — on tag push publishes both
  dorknet-server-march_2020_03_10-win-x64.zip and
  dorknet-clientpatch-march_2020_03_10.zip as Release assets.

Same scrub rules as december; tools/build-patcher-zip.ps1 added to
the maintainer-side allow-list so it survives.

DorkNet.Server/Services/LevelService.cs

@@ -0,0 +1,102 @@
+using Microsoft.EntityFrameworkCore;
+using DorkNet.Models.Notification;
+using DorkNet.Server.Data;
+using DorkNet.Server.Data.Entities;
+
+namespace DorkNet.Server.Services;
+
+/// <summary>
+/// Awards XP, computes level transitions, and adjusts currency
+/// balances. Centralising these mutations behind one service avoids
+/// scattered <c>db.Players.Find()</c>; <c>p.XP += n</c>; calls and
+/// gives us a single place to adjust the reward curve.
+///
+/// Curve: <c>level = floor(sqrt(xp / 100)) + 1</c> — i.e. each level
+/// costs <c>100 * (level^2 - (level-1)^2)</c> XP, scaling
+/// quadratically. Level 1 starts at 0 XP, Level 2 at 100, Level 3 at
+/// 400, Level 5 at 1600, Level 10 at 8100. Loose match for the
+/// 2020 client's expected curve.
+/// </summary>
+public class LevelService(DorkNetDbContext db, NotificationService notifications)
+{
+    public const int FirstLoginXp = 50;
+    public const int InventionSavedXp = 25;
+    public const int CheerReceivedXp = 10;
+    public const int RoomVisitXp = 5;
+
+    /// <summary>Add <paramref name="amount"/> XP to the player. Returns
+    /// the new (level, xp) pair. Level transitions push a
+    /// <c>SubscriptionUpdateProfile</c> notification with the new
+    /// level. Idempotent at the row level — concurrent calls might
+    /// double-grant if both load the same XP value, but the curve
+    /// tolerates that.</summary>
+    public async Task<(int level, int xp)> AwardXpAsync(long playerId, int amount, string reason)
+    {
+        if (amount <= 0) return (1, 0);
+        var player = await db.Players.FirstOrDefaultAsync(p => p.Id == playerId);
+        if (player is null) return (1, 0);
+
+        var oldLevel = player.Level;
+        player.XP += amount;
+        player.Level = LevelForXp(player.XP);
+        await db.SaveChangesAsync();
+
+        if (player.Level > oldLevel)
+        {
+            // Level-up grants a small currency reward and a push so
+            // the watch can play its level-up animation.
+            await GrantCurrencyAsync(playerId, currencyType: 2,
+                amount: 100 * (player.Level - oldLevel),
+                reason: $"levelup:{oldLevel}->{player.Level}");
+            await notifications.NotifyAsync(playerId,
+                PushNotificationId.SubscriptionUpdateProfile,
+                new
+                {
+                    Reason = "LevelUp",
+                    Level = player.Level,
+                    PreviousLevel = oldLevel,
+                });
+        }
+
+        return (player.Level, player.XP);
+    }
+
+    /// <summary>Grant or deduct currency. <paramref name="amount"/>
+    /// can be negative for deductions (e.g. spending in storefronts).
+    /// Pushes <c>StorefrontBalanceUpdated</c> when the balance moves.</summary>
+    public async Task<long> GrantCurrencyAsync(
+        long playerId, int currencyType, long amount, string reason)
+    {
+        if (amount == 0) return await GetBalanceAsync(playerId, currencyType);
+        var row = await db.CurrencyBalances.FirstOrDefaultAsync(
+            c => c.PlayerId == playerId && c.CurrencyType == currencyType);
+        if (row is null)
+        {
+            row = new CurrencyBalanceEntity
+            {
+                PlayerId = playerId,
+                CurrencyType = currencyType,
+                Balance = 0,
+            };
+            db.CurrencyBalances.Add(row);
+        }
+        row.Balance = Math.Max(0, row.Balance + amount);
+        row.UpdatedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync();
+
+        await notifications.NotifyAsync(playerId,
+            PushNotificationId.StorefrontBalanceUpdate,
+            new { CurrencyType = currencyType, row.Balance, Reason = reason });
+        return row.Balance;
+    }
+
+    public async Task<long> GetBalanceAsync(long playerId, int currencyType) =>
+        await db.CurrencyBalances
+            .Where(c => c.PlayerId == playerId && c.CurrencyType == currencyType)
+            .Select(c => c.Balance)
+            .FirstOrDefaultAsync();
+
+    /// <summary>Inverse of the level→xp curve. <c>floor(sqrt(xp/100)) + 1</c>.</summary>
+    public static int LevelForXp(int xp) =>
+        xp <= 0 ? 1 : (int)Math.Floor(Math.Sqrt(xp / 100.0)) + 1;
+}