Add a cheap total chunk count to the index store

app/MindWork AI Studio/Tools/Databases/DatabaseClient.cs

@@ -8,11 +8,20 @@ public abstract class DatabaseClient(string name, string path)
 
     public virtual DatabaseClientStatus Status => DatabaseClientStatus.AVAILABLE;
 
+    /// <summary>
+    /// The version the running database reports about itself.
+    /// </summary>
+    /// <remarks>
+    /// Empty when the client cannot tell. Callers which want to show a version in a headline read it
+    /// from here instead of picking it out of the label-value pairs the display info yields.
+    /// </remarks>
+    public virtual string Version => string.Empty;
+
     public bool IsAvailable => this.Status is DatabaseClientStatus.AVAILABLE;
     
     private string Path => path;
 
-    private ILogger<DatabaseClient>? logger;
+    protected ILogger<DatabaseClient>? Logger;
     
     public abstract IAsyncEnumerable<(string Label, string Value)> GetDisplayInfo();
 
@@ -20,13 +29,13 @@ public abstract class DatabaseClient(string name, string path)
     {
         if (string.IsNullOrWhiteSpace(this.Path))
         {
-            this.logger!.LogError($"Error: Database path '{this.Path}' cannot be null or empty.");
+            this.Logger!.LogError($"Error: Database path '{this.Path}' cannot be null or empty.");
             return "0 B";
         }
 
         if (!Directory.Exists(this.Path))
         {
-            this.logger!.LogError($"Error: Database path '{this.Path}' does not exist.");
+            this.Logger!.LogError($"Error: Database path '{this.Path}' does not exist.");
             return "0 B";
         }
         var files = Directory.EnumerateFiles(this.Path, "*", SearchOption.AllDirectories)
@@ -52,7 +61,7 @@ public abstract class DatabaseClient(string name, string path)
     
     public void SetLogger(ILogger<DatabaseClient> logService)
     {
-        this.logger = logService;
+        this.Logger = logService;
     }
 
     public abstract void Dispose();

app/MindWork AI Studio/Tools/Databases/IndexStore/IndexStoreClient.cs

@@ -40,4 +40,17 @@ public abstract class IndexStoreClient(string name, string path) : DatabaseClien
     public abstract Task<IReadOnlyList<IndexStoreSearchResult>> SearchChunksAsync(string dataSourceId, string query, int maxMatches, CancellationToken token);
 
     public abstract Task DeleteDataSourceAsync(string dataSourceId, CancellationToken token);
+
+    /// <summary>
+    /// Counts the search chunks the index holds across all data sources.
+    /// </summary>
+    /// <remarks>
+    /// One chunk is one vector: every chunk becomes exactly one point carrying the single named
+    /// vector "embedding". The vector store reports its vector count from here, because counting
+    /// the points in Qdrant Edge would have to load every shard first and would hold the global
+    /// database mutex against ongoing inserts and searches while doing so.
+    /// </remarks>
+    /// <param name="token">The cancellation token.</param>
+    /// <returns>The number of chunks, or null when the index cannot tell. Null and zero mean different things here.</returns>
+    public abstract Task<long?> GetTotalChunkCountAsync(CancellationToken token);
 }

app/MindWork AI Studio/Tools/Databases/IndexStore/NoIndexStoreClient.cs

@@ -55,6 +55,8 @@ public sealed class NoIndexStoreClient(string name, string? unavailableReason, D
 
     public override Task DeleteDataSourceAsync(string dataSourceId, CancellationToken token) => Task.CompletedTask;
 
+    public override Task<long?> GetTotalChunkCountAsync(CancellationToken token) => Task.FromResult<long?>(null);
+
     public override void Dispose()
     {
     }

app/MindWork AI Studio/Tools/Databases/IndexStore/SqliteIndexStoreClientImplementation.cs

@@ -25,6 +25,8 @@ public sealed class SqliteIndexStoreClientImplementation(string name, string dat
 
     public override string CacheKey => $"{this.Name}:{this.databasePath}:{version}";
 
+    public override string Version => version;
+
     public static async Task<DatabaseClient> CreateAsync(
         ILogger logger,
         ILogger<DatabaseClient> databaseClientLogger,
@@ -65,7 +67,8 @@ public sealed class SqliteIndexStoreClientImplementation(string name, string dat
         yield return (TB("Storage size"), this.GetStorageSize());
         yield return (TB("Indexed data sources"), (await context.DataSources.CountAsync(CancellationToken.None)).ToString(CultureInfo.InvariantCulture));
         yield return (TB("Indexed files"), (await context.EmbeddedFiles.CountAsync(CancellationToken.None)).ToString(CultureInfo.InvariantCulture));
-        yield return (TB("Search chunks"), (await context.EmbeddingChunks.CountAsync(CancellationToken.None)).ToString(CultureInfo.InvariantCulture));
+        var searchChunks = await this.GetTotalChunkCountAsync(CancellationToken.None);
+        yield return (TB("Search chunks"), searchChunks?.ToString(CultureInfo.InvariantCulture) ?? TB("unknown"));
         yield return (TB("Permanently skipped files"), (await context.PermanentIndexingFailures.CountAsync(CancellationToken.None)).ToString(CultureInfo.InvariantCulture));
     }
 
@@ -348,6 +351,27 @@ public sealed class SqliteIndexStoreClientImplementation(string name, string dat
         await transaction.CommitAsync(token);
     }
 
+    public override async Task<long?> GetTotalChunkCountAsync(CancellationToken token)
+    {
+        try
+        {
+            await using var context = this.CreateContext();
+
+            //
+            // Sum the chunk counts the files carry instead of counting the rows of the chunk table:
+            // embedded_files holds one row per file, embedding_chunks one per chunk. On a large index
+            // that is a difference of two orders of magnitude, and the information page reads this on
+            // every visit.
+            //
+            return await context.EmbeddedFiles.SumAsync(file => (long)file.ChunkCount, token);
+        }
+        catch (Exception exception)
+        {
+            this.Logger?.LogWarning(exception, "Failed to count the search chunks of the local RAG index.");
+            return null;
+        }
+    }
+
     public override void Dispose()
     {
     }