Prompt History und Verbrauchsauswertung (#660), englische Hauptsprache (#661)

Prompt history: every run records its transcript (task, each model step with
tokens and cost, tool calls and results, engine follow-ups) - bounded in size,
scrubbed of recognisable secrets, system prompts stored once per text.
Retention in days per instance (default 14) and per agent (0 = never, -1 =
forever); an hourly janitor deletes what is past it, "never" also purges.

Usage analysis over run receipts: filter by period, agent, model, event, status,
cost and free text; sort by every column; totals over the whole filter; hourly
or daily series grouped by agent, model or event; markers for budget denials and
model changes; run detail with receipt, transcript, tool calls and approvals.

WebUI: Analysis > Token usage > Runs / Timeline, run detail, Prompt History with
retention settings. New code, comments and texts in English; texts come from
language packs (i18n/en.json, de.json) via modules/i18n.js. CLAUDE.md records
English as the main language.

Version 0.1.12.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/ClawdDotNet.App/AppHost.cs

@@ -98,6 +98,12 @@ public sealed class AppHost : IAsyncDisposable
     public TaskboardService? Board { get; private init; }
     public SqliteUsageRepository? Usage { get; private init; }
 
+    /// <summary>#660: Prompt history - prompt and response of every run.</summary>
+    public Core.Transcripts.IRunTranscriptStore? Transcripts { get; private init; }
+
+    /// <summary>#660: Usage analysis, run details and prompt history for the user interfaces.</summary>
+    public RunInsights? Insights { get; private init; }
+
     /// <summary>Modellpreise von OpenRouter - fuer Budget und Kostenprognose (#595). Laedt im Hintergrund.</summary>
     public ModelPricingCatalog? Pricing { get; private init; }
 
@@ -525,6 +531,7 @@ public sealed class AppHost : IAsyncDisposable
         var dauerfreigaben = new SqliteDauerfreigabeRepository(storage);
         var stagingGate = new StagingGate(new StagingPolicy(), stagingRepository, dauerfreigaben: dauerfreigaben);
         var usage = new SqliteUsageRepository(storage);
+        var transcripts = new Core.Transcripts.SqliteRunTranscriptStore(storage);
 
         // Preise fürs Budget: Ohne sie greift nur die Token-Grenze.
         var pricing = new ModelPricingCatalog();
@@ -539,6 +546,8 @@ public sealed class AppHost : IAsyncDisposable
             memory, usage, pricing, taskRepository, audit, stagingGate)
         {
             InstanceBudget = instance.Budget,
+            TranscriptStore = transcripts,
+            DefaultTranscriptRetention = () => instance.PromptHistory.RetentionDays,
             MaxDelegationDepth = instance.MaxDelegationDepth,
             DelegationGateTimeout = TimeSpan.FromSeconds(instance.DelegationGateTimeoutSeconds)
         };
@@ -574,6 +583,11 @@ public sealed class AppHost : IAsyncDisposable
             Staging = staging,
             Board = board,
             Usage = usage,
+            Transcripts = transcripts,
+            Insights = new RunInsights(audit, transcripts, board, staging,
+                agentId => instance.Agents.FirstOrDefault(a => a.AgentId == agentId) is { } agent
+                    ? engine.TranscriptRetentionFor(agent)
+                    : Core.Transcripts.PromptHistorySettings.Normalize(instance.PromptHistory.RetentionDays)),
             Pricing = pricing,
             TelegramClient = telegram,
             Status = new OpenRouterStatusService(instance.OpenRouterApiKey),
@@ -591,6 +605,16 @@ public sealed class AppHost : IAsyncDisposable
 
         host._shutdown.Add(() => { openRouter.Dispose(); return ValueTask.CompletedTask; });
 
+        // #660: Retention of the prompt history - per agent, falling back to the instance.
+        var janitor = new Core.Transcripts.TranscriptJanitor(
+            transcripts,
+            agentId => instance.Agents.FirstOrDefault(a => a.AgentId == agentId) is { } agent
+                ? engine.TranscriptRetentionFor(agent)
+                : Core.Transcripts.PromptHistorySettings.Normalize(instance.PromptHistory.RetentionDays),
+            loggerFactory.CreateLogger("ClawdDotNet.Core.Transcripts"));
+        janitor.Start();
+        host._shutdown.Add(janitor.DisposeAsync);
+
         // #593: Angelegt wurde der Dienst schon immer, gestartet nie — weder kopflos noch
         // mit Fenster. Die Kopfzeile der Weboberflaeche stand deshalb dauerhaft auf
         // "OpenRouter: —" und /api/status auf "Prüfe…".