Auto-Context: Semantische Kontext-Injektion, Memory-File-Embeddings, Agent-Toggle

- Automatische Embedding-basierte Kontext-Injektion vor jeder API-Anfrage
  (Top 5 Chat-Ergebnisse + Top 3 Memory-File-Treffer als recalled_context)
- Memory-Dateien (.md) werden embedded (Backfill + Live nach memory_write)
- Neue Agent-Option 'useAutoContext' (Checkbox, Default: aktiviert)
- VectorSearchService: SearchMemoryFilesAsync, EmbedMemoryFileAsync, Chunking
- EmbeddingBackgroundService: Memory-File-Backfill + EnqueueMemoryFile
- ToolService: memory_write löst Re-Embedding aus
- embeddingBg Parameter an ExecuteTool durchgereicht

Services/EmbeddingBackgroundService.cs

@@ -1,4 +1,5 @@
 using System;
+using System.IO;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Threading;
@@ -21,12 +22,14 @@ public class EmbeddingBackgroundService : BackgroundService
     readonly string _dbConnectionString;
     readonly ConcurrentQueue<EmbeddingJob> _queue = new();
     readonly SemaphoreSlim _signal = new(0);
+    readonly string _dataPath;
 
     public EmbeddingBackgroundService(VectorSearchService vectorSearch, EmbeddingService embedding, string dbPath)
     {
         _vectorSearch = vectorSearch;
         _embedding = embedding;
         _dbConnectionString = $"Data Source={dbPath}";
+        _dataPath = Path.GetDirectoryName(dbPath);
     }
 
     /// <summary>Enqueue eine neue Message zum Embedden.</summary>
@@ -50,6 +53,9 @@ public class EmbeddingBackgroundService : BackgroundService
         // Backfill bestehender Messages
         await BackfillAsync(ct);
 
+        // Memory-Dateien embedden
+        await BackfillMemoryFilesAsync(ct);
+
         // Live-Embedding neuer Messages
         Console.WriteLine("[EmbeddingBG] Waiting for new messages...");
         while (!ct.IsCancellationRequested)
@@ -62,12 +68,21 @@ public class EmbeddingBackgroundService : BackgroundService
                     if (ct.IsCancellationRequested) break;
                     try
                     {
-                        await _vectorSearch.EmbedMessageAsync(job.MessageId, job.ChainId, job.SessionId,
-                            job.AgentId, job.Role, job.Text);
+                        if (job.Role.StartsWith("memory:"))
+                        {
+                            // Memory-File-Embedding
+                            var filePath = job.Role.Substring("memory:".Length);
+                            await _vectorSearch.EmbedMemoryFileAsync(job.AgentId, filePath, job.Text);
+                        }
+                        else
+                        {
+                            await _vectorSearch.EmbedMessageAsync(job.MessageId, job.ChainId, job.SessionId,
+                                job.AgentId, job.Role, job.Text);
+                        }
                     }
                     catch (Exception ex)
                     {
-                        Console.WriteLine($"[EmbeddingBG] Error embedding message {job.MessageId}: {ex.Message}");
+                        Console.WriteLine($"[EmbeddingBG] Error embedding job: {ex.Message}");
                     }
                 }
             }
@@ -133,6 +148,54 @@ public class EmbeddingBackgroundService : BackgroundService
         Console.WriteLine($"[EmbeddingBG] Backfill complete: {embedded} new embeddings, {skipped} skipped, {total} total messages.");
     }
 
+    async Task BackfillMemoryFilesAsync(CancellationToken ct)
+    {
+        Console.WriteLine("[EmbeddingBG] Starting memory file backfill...");
+
+        var agentsDir = Path.Combine(_dataPath, "agents");
+        if (!Directory.Exists(agentsDir))
+        {
+            Console.WriteLine("[EmbeddingBG] No agents directory found, skipping memory backfill.");
+            return;
+        }
+
+        int total = 0;
+        foreach (var agentDir in Directory.GetDirectories(agentsDir))
+        {
+            if (ct.IsCancellationRequested) break;
+            var agentId = Path.GetFileName(agentDir);
+
+            // Alle .md Dateien im Agent-Verzeichnis (rekursiv)
+            var mdFiles = Directory.GetFiles(agentDir, "*.md", SearchOption.AllDirectories);
+            foreach (var mdFile in mdFiles)
+            {
+                if (ct.IsCancellationRequested) break;
+                try
+                {
+                    var text = await File.ReadAllTextAsync(mdFile, ct);
+                    if (string.IsNullOrWhiteSpace(text) || text.Length < 10) continue;
+
+                    var relativePath = Path.GetRelativePath(agentDir, mdFile);
+                    await _vectorSearch.EmbedMemoryFileAsync(agentId, relativePath, text);
+                    total++;
+                }
+                catch (Exception ex)
+                {
+                    Console.WriteLine($"[EmbeddingBG] Error embedding memory file {mdFile}: {ex.Message}");
+                }
+            }
+        }
+
+        Console.WriteLine($"[EmbeddingBG] Memory file backfill complete: {total} files embedded.");
+    }
+
+    /// <summary>Embeddet eine einzelne Memory-Datei (nach memory_write).</summary>
+    public void EnqueueMemoryFile(string agentId, string filePath, string text)
+    {
+        _queue.Enqueue(new EmbeddingJob(0, "", "", agentId, "memory:" + filePath, text));
+        _signal.Release();
+    }
+
     record EmbeddingJob(long MessageId, string ChainId, string SessionId, string AgentId, string Role, string Text);
 
     class BackfillRow