fix: record Astra chat token usage for ORB-7

architecture.json

@@ -7258,6 +7258,7 @@
         "testClass": "AccountDeletionServiceDbTests",
         "file": "tests/Orbit.Infrastructure.Tests/Services/AccountDeletionServiceDbTests.cs",
         "references": [
+          "AiUsageDaily",
           "LogHabitCommand",
           "ProcessedRequest",
           "SentProactiveCheckin",

src/Orbit.Domain/Entities/AiUsageDaily.cs

@@ -12,14 +12,16 @@ public record AiUsageTotals(
     decimal CostUsd);
 
 /// <summary>
-/// Aggregated AI token usage and computed dollar cost for a single (UTC date, model, purpose) triple.
+/// Aggregated AI token usage and computed dollar cost for a single
+/// (UTC date, model, purpose, optional user) tuple.
 /// Rows are UPSERTed at the AI completion chokepoint and read once per day by the usage-summary job.
 /// </summary>
 public class AiUsageDaily : Entity
 {
     public DateOnly Date { get; private set; }
     public string Model { get; private set; } = string.Empty;
     public string Purpose { get; private set; } = string.Empty;
+    public Guid? UserId { get; private set; }
     public long Calls { get; private set; }
     public long CachedTokens { get; private set; }
     public long PromptTokens { get; private set; }
@@ -33,13 +35,15 @@ public static AiUsageDaily Create(
         DateOnly date,
         string model,
         string purpose,
-        AiUsageTotals totals)
+        AiUsageTotals totals,
+        Guid? userId = null)
     {
         return new AiUsageDaily
         {
             Date = date,
             Model = model,
             Purpose = purpose,
+            UserId = userId,
             Calls = totals.Calls,
             CachedTokens = totals.CachedTokens,
             PromptTokens = totals.PromptTokens,

src/Orbit.Domain/Interfaces/IAiUsageRecorder.cs

@@ -6,12 +6,13 @@
 /// </summary>
 public interface IAiUsageRecorder
 {
     Task RecordAsync(
         string purpose,
         string model,
         long cachedTokens,
         long promptTokens,
         long completionTokens,
         long totalTokens,
-        CancellationToken cancellationToken = default);
+        CancellationToken cancellationToken = default,
+        Guid? userId = null);
 }

src/Orbit.Domain/Models/AiToolModels.cs

@@ -38,6 +38,8 @@ public sealed class AiConversationContext
     public object Messages { get; init; } = null!;
     /// <summary>Opaque options object. Only consumed by AiIntentService.</summary>
     public object Options { get; init; } = null!;
+    /// <summary>User attributed to each model round in this conversation.</summary>
+    public Guid? UserId { get; init; }
 }
 
 public record AiResponse

src/Orbit.Infrastructure/AI/AiCompletionClient.cs

@@ -80,6 +80,8 @@ internal AiCompletionClient(
     /// </summary>
     public ChatClient ChatClient => _chatClient;
 
+    internal string ChatModel => _primaryModel;
+
     /// <summary>
     /// Requests a plain-text chat completion from the configured model tier.
     /// </summary>

src/Orbit.Infrastructure/AI/AiUsageRecorder.cs

@@ -10,9 +10,10 @@ namespace Orbit.Infrastructure.AI;
 
 /// <summary>
 /// Singleton recorder that converts one completion's tokens into a dollar cost from the configured
-/// per-model price map and atomically UPSERTs it into the daily (date, model, purpose) aggregate via a
-/// child DI scope, so the singleton AI client never holds a scoped DbContext. Best-effort: any write
-/// failure is logged once at Warning and swallowed so the user's AI response is never affected.
+/// per-model price map and atomically UPSERTs it into the daily
+/// (date, model, purpose, optional user) aggregate via a child DI scope, so the singleton AI client
+/// never holds a scoped DbContext. Best-effort: any write failure is logged once at Warning and
+/// swallowed so the user's AI response is never affected.
 /// </summary>
 public sealed partial class AiUsageRecorder(
     IServiceScopeFactory scopeFactory,
@@ -30,7 +31,8 @@ public async Task RecordAsync(
         long promptTokens,
         long completionTokens,
         long totalTokens,
-        CancellationToken cancellationToken = default)
+        CancellationToken cancellationToken = default,
+        Guid? userId = null)
     {
         var costUsd = ComputeCostUsd(_pricing.GetValueOrDefault(model), cachedTokens, promptTokens, completionTokens);
 #pragma warning disable ORBIT0004 // WHY: pre-existing deliberate UTC-date window or UTC-keyed dedupe/aggregation bucket (not a user's calendar date), per-site justification ledger: https://github.com/thomasluizon/orbit-api/issues/431
@@ -43,9 +45,9 @@ public async Task RecordAsync(
             var dbContext = scope.ServiceProvider.GetRequiredService<OrbitDbContext>();
             await dbContext.Database.ExecuteSqlInterpolatedAsync($"""
                 INSERT INTO "AiUsageDaily"
-                    ("Id", "Date", "Model", "Purpose", "Calls", "CachedTokens", "PromptTokens", "CompletionTokens", "TotalTokens", "CostUsd")
-                VALUES ({Guid.NewGuid()}, {date}, {model}, {purpose}, 1, {cachedTokens}, {promptTokens}, {completionTokens}, {totalTokens}, {costUsd})
-                ON CONFLICT ("Date", "Model", "Purpose") DO UPDATE SET
+                    ("Id", "Date", "Model", "Purpose", "UserId", "Calls", "CachedTokens", "PromptTokens", "CompletionTokens", "TotalTokens", "CostUsd")
+                VALUES ({Guid.NewGuid()}, {date}, {model}, {purpose}, {userId}, 1, {cachedTokens}, {promptTokens}, {completionTokens}, {totalTokens}, {costUsd})
+                ON CONFLICT ("Date", "Model", "Purpose", "UserId") DO UPDATE SET
                     "Calls" = "AiUsageDaily"."Calls" + 1,
                     "CachedTokens" = "AiUsageDaily"."CachedTokens" + EXCLUDED."CachedTokens",
                     "PromptTokens" = "AiUsageDaily"."PromptTokens" + EXCLUDED."PromptTokens",