Raise habit ceiling to abuse guard

architecture.json

@@ -2720,7 +2720,7 @@
       "Challenges": 15,
       "Chat": 80,
       "ChecklistTemplates": 5,
-      "Common": 35,
+      "Common": 36,
       "Gamification": 31,
       "Goals": 35,
       "Habits": 74,
@@ -2929,10 +2929,10 @@
       "Challenges": 14,
       "Chat": 61,
       "ChecklistTemplates": 9,
-      "Common": 178,
+      "Common": 184,
       "Gamification": 38,
       "Goals": 54,
-      "Habits": 86,
+      "Habits": 87,
       "Marketing": 6,
       "Notifications": 19,
       "Profile": 40,
@@ -3610,7 +3610,8 @@
         "testClass": "MoveHabitToolTests",
         "file": "tests/Orbit.Application.Tests/Chat/Tools/MoveHabitToolTests.cs",
         "references": [
-          "Habit"
+          "Habit",
+          "MoveHabitParentCommand"
         ]
       },
       {
@@ -4823,6 +4824,13 @@
         "file": "tests/Orbit.Application.Tests/Common/ErrorCodesAndMessagesTests.cs",
         "references": []
       },
+      {
+        "testClass": "HabitCeilingLockTests",
+        "file": "tests/Orbit.Application.Tests/Common/HabitCeilingLockTests.cs",
+        "references": [
+          "Habit"
+        ]
+      },
       {
         "testClass": "LocaleHelperTests",
         "file": "tests/Orbit.Application.Tests/Common/LocaleHelperTests.cs",

src/Orbit.Application/Chat/Content/FeatureExplanations/paygate.md

@@ -13,11 +13,11 @@ derived_from:
 
 # Free vs Pro
 
-Orbit has a free plan and a Pro plan. The free plan is fully usable for daily habit tracking; Pro raises the limits and unlocks the advanced features.
+Orbit has a free plan and a Pro plan. The free plan is fully usable for daily habit tracking; Pro raises the AI message limit and unlocks advanced features.
 
 ## Limits on the free plan
 
-- **Habits** are capped at **10** top-level habits. Sub-habits, completed habits, and soft-deleted habits don't count toward the cap. Pro removes the cap.
+- **Habits** have an abuse guard of **1000** live top-level habits on both the free and Pro plans. Sub-habits, completed habits, and soft-deleted habits don't count toward the guard.
 - **AI messages** are capped at **20** per month. Pro raises this to **500** per month.
 
 Both plans can also earn a small bonus of extra AI messages from ad rewards, added on top of the plan limit.

src/Orbit.Application/Chat/Tools/Implementations/CreateHabitTool.cs

@@ -1,6 +1,7 @@
 using System.Text.Json;
 using Orbit.Application.Chat.Models;
 using Orbit.Application.Chat.Tools;
+using Orbit.Application.Common;
 using Orbit.Domain.Entities;
 using Orbit.Domain.Enums;
 using Orbit.Domain.Interfaces;
@@ -149,6 +150,19 @@ public async Task<ToolResult> ExecuteAsync(JsonElement args, Guid userId, Cancel
 
         var title = titleEl.GetString() ?? string.Empty;
 
+        return await HabitCeilingLock.ExecuteAsync(
+            unitOfWork,
+            userId,
+            transactionToken => ExecuteLockedAsync(args, userId, title, transactionToken),
+            ct);
+    }
+
+    private async Task<ToolResult> ExecuteLockedAsync(
+        JsonElement args,
+        Guid userId,
+        string title,
+        CancellationToken ct)
+    {
         var habitGate = await payGate.CanCreateHabits(userId, 1, ct);
         if (habitGate.IsFailure)
             return ToolResult.FromFailure(habitGate);

src/Orbit.Application/Chat/Tools/Implementations/MoveHabitParentTool.cs

@@ -40,15 +40,16 @@
             parentId = parsedParentId;
         }
 
-        var habit = await HabitToolHelpers.FindHabitAsync(habitRepository, habitId, userId, ct);
-        if (habit is null)
-            return HabitToolHelpers.HabitNotFoundResult(habitId);
-
         var result = await mediator.Send(new MoveHabitParentCommand(userId, habitId, parentId), ct);
 
         if (result.IsFailure)
             return ToolResult.FromFailure(result);
 
-        return new ToolResult(true, EntityId: habitId.ToString(), EntityName: habit.Title);
+        var habits = await habitRepository.FindAsync(
+            habit => habit.Id == habitId && habit.UserId == userId, ct);
+        return new ToolResult(
+            true,
+            EntityId: habitId.ToString(),
+            EntityName: habits.FirstOrDefault()?.Title);
     }
 }

src/Orbit.Application/Chat/Tools/Implementations/MoveHabitTool.cs

@@ -1,10 +1,13 @@
 using System.Text.Json;
+using MediatR;
+using Orbit.Application.Habits.Commands;
 using Orbit.Domain.Entities;
 using Orbit.Domain.Interfaces;
 
 namespace Orbit.Application.Chat.Tools.Implementations;
 
 public class MoveHabitTool(
+    IMediator mediator,
     IGenericRepository<Habit> habitRepository) : IAiTool
 {
     public string Name => "move_habit";
@@ -28,66 +31,22 @@
         if (!HabitToolHelpers.TryParseHabitId(args, out var habitId))
             return HabitToolHelpers.InvalidHabitIdResult();
 
-        var habit = await HabitToolHelpers.FindHabitAsync(habitRepository, habitId, userId, ct);
-        if (habit is null)
-            return HabitToolHelpers.HabitNotFoundResult(habitId);
-
         Guid? newParentId = null;
         if (args.TryGetProperty("new_parent_id", out var parentEl)
             && parentEl.ValueKind == JsonValueKind.String
             && Guid.TryParse(parentEl.GetString(), out var parsedParentId))
-        {
-            var parent = await habitRepository.FindOneTrackedAsync(
-                h => h.Id == parsedParentId && h.UserId == userId,
-                cancellationToken: ct);
-
-            if (parent is null)
-                return new ToolResult(false, Error: $"New parent habit {parsedParentId} not found.");
-
-            if (parsedParentId == habitId)
-                return new ToolResult(false, Error: "A habit cannot be its own parent.");
-
-            if (await WouldCreateCycleAsync(habitId, parsedParentId, userId, ct))
-                return new ToolResult(false, Error: "Cannot move habit: this would create a circular parent chain.");
-
             newParentId = parsedParentId;
-        }
-
-        habit.SetParentHabitId(newParentId);
-
-        return new ToolResult(true, EntityId: habit.Id.ToString(), EntityName: habit.Title);
-    }
-
-    /// <summary>
-    /// Walks up the ancestor chain of <paramref name="candidateParentId"/> and returns true
-    /// if <paramref name="habitId"/> appears anywhere in that chain, which would create a cycle.
-    /// </summary>
-    private async Task<bool> WouldCreateCycleAsync(Guid habitId, Guid candidateParentId, Guid userId, CancellationToken ct)
-    {
-        var visited = new HashSet<Guid>();
-        var current = candidateParentId;
-
-        while (true)
-        {
-            if (!visited.Add(current))
-                break;
-            var ancestors = await habitRepository.FindAsync(
-                h => h.Id == current && h.UserId == userId,
-                ct);
-            var ancestor = ancestors.Count > 0 ? ancestors[0] : null;
-
-            if (ancestor is null)
-                break;
-
-            if (ancestor.ParentHabitId is null)
-                break;
-
-            if (ancestor.ParentHabitId.Value == habitId)
-                return true;
-
-            current = ancestor.ParentHabitId.Value;
-        }
 
-        return false;
+        var result = await mediator.Send(
+            new MoveHabitParentCommand(userId, habitId, newParentId), ct);
+        if (result.IsFailure)
+            return ToolResult.FromFailure(result);
+
+        var habits = await habitRepository.FindAsync(
+            habit => habit.Id == habitId && habit.UserId == userId, ct);
+        return new ToolResult(
+            true,
+            EntityId: habitId.ToString(),
+            EntityName: habits.FirstOrDefault()?.Title);
     }
 }

src/Orbit.Application/Chat/Tools/Implementations/UpdateHabitTool.cs

@@ -2,6 +2,7 @@
 using System.Text.Json;
 using Orbit.Application.Chat.Tools;
 using Orbit.Application.Common;
+using Orbit.Domain.Common;
 using Orbit.Domain.Entities;
 using Orbit.Domain.Enums;
 using Orbit.Domain.Interfaces;
@@ -12,7 +13,8 @@ namespace Orbit.Application.Chat.Tools.Implementations;
 public class UpdateHabitTool(
     IGenericRepository<Habit> habitRepository,
     IUserDateService userDateService,
-    IPayGateService? payGate = null) : IAiTool
+    IUnitOfWork unitOfWork,
+    IPayGateService payGate) : IAiTool
 {
     public string Name => "update_habit";
 
@@ -93,30 +95,53 @@ public async Task<ToolResult> ExecuteAsync(JsonElement args, Guid userId, Cancel
         if (!HabitToolHelpers.TryParseHabitId(args, out var habitId))
             return HabitToolHelpers.InvalidHabitIdResult();
 
-        var habit = await HabitToolHelpers.FindHabitAsync(habitRepository, habitId, userId, ct);
-        if (habit is null)
-            return HabitToolHelpers.HabitNotFoundResult(habitId);
-
-        var today = await userDateService.GetUserTodayAsync(userId, ct);
-        var updateParams = ResolveUpdateParams(args, habit, today);
-
-        var result = await HabitReactivationAllowance.ExecuteAsync(
+        var result = await HabitCeilingLock.ExecuteEntryAsync<UpdateToolState, ToolResult>(
+            unitOfWork,
             userId,
-            HabitReactivationAllowance.IsRequiredForEndDateChange(
-                habit,
-                updateParams.FrequencyUnit,
-                updateParams.DueDate,
-                updateParams.EndDate,
-                updateParams.ClearEndDate == true),
             payGate,
-            () => habit.Update(updateParams),
+            transactionToken => PrepareUpdateAsync(args, habitId, userId, transactionToken),
+            state => HabitLiveRootEntry.FromUpdate(state.Habit, state.Update),
+            ApplyUpdateAsync,
             ct);
+
         if (result.IsFailure)
             return ToolResult.FromFailure(result);
 
-        return new ToolResult(true, EntityId: habit.Id.ToString(), EntityName: habit.Title);
+        return result.Value;
     }
 
+    private async Task<Result<UpdateToolState>> PrepareUpdateAsync(
+        JsonElement args,
+        Guid habitId,
+        Guid userId,
+        CancellationToken cancellationToken)
+    {
+        var habit = await HabitToolHelpers.FindHabitAsync(
+            habitRepository, habitId, userId, cancellationToken);
+        if (habit is null)
+            return Result.Failure<UpdateToolState>($"Habit {habitId} not found.");
+
+        var today = await userDateService.GetUserTodayAsync(userId, cancellationToken);
+        return Result.Success(new UpdateToolState(habit, ResolveUpdateParams(args, habit, today)));
+    }
+
+    private async Task<Result<ToolResult>> ApplyUpdateAsync(
+        UpdateToolState state,
+        CancellationToken cancellationToken)
+    {
+        var result = state.Habit.Update(state.Update);
+        if (result.IsFailure)
+            return result.PropagateError<ToolResult>();
+
+        await unitOfWork.SaveChangesAsync(cancellationToken);
+        return Result.Success(new ToolResult(
+            true,
+            EntityId: state.Habit.Id.ToString(),
+            EntityName: state.Habit.Title));
+    }
+
+    private sealed record UpdateToolState(Habit Habit, HabitUpdateParams Update);
+
     /// <summary>
     /// Resolve each field: absent = keep existing, null = clear, value = update.
     /// Extracted to reduce ExecuteAsync cognitive complexity.

src/Orbit.Application/Common/AppConstants.cs

@@ -17,7 +17,7 @@ public static class AppConstants
     public const int HabitLogsLookbackDays = 365;
     public const int MaxHabitLogsReturned = 1000;
     public const int DefaultReminderMinutes = 15;
-    public const int DefaultFreeMaxHabits = 10;
+    public const int DefaultFreeMaxHabits = 1000;
     public const int DefaultFreeAiMessages = 20;
     public const int DefaultProAiMessages = 500;
     public const int MaxBulkOperationSize = 100;