feat: Introduce a /reset command to clear the chat session and token tracking, and update documentation.

Tools/FileTools.cs

@@ -14,7 +14,13 @@ internal static class FileTools
 {
     public static Action<string> Log { get; set; } = Console.WriteLine;
 
-    [Description("Read a file. Max 200 lines per call. Returns lines with line:hash| anchors.")]
+    /// <summary>
+    /// Optional callback invoked after each successful ReadFile call, with the resolved path.
+    /// Set by ReplLoop to trigger deduplication compaction while the tool loop is still active.
+    /// </summary>
+    public static Action<string>? OnFileRead { get; set; }
+
+    [Description("Read a file. Max 200 lines per call. Returns lines with line:hash| anchors. IMPORTANT: Call GrepFile first (pattern: 'public|class|func|interface|enum|def') to get a structural outline and target startLine/endLine before calling this.")]
     public static string ReadFile(
         [Description("Path to the file.")] string path,
         [Description("First line to return (inclusive). Defaults to 1.")] int startLine = 1,
@@ -40,7 +46,9 @@ internal static class FileTools
                 return $"ERROR: File too large to read at once ({lines.Length} lines). Provide startLine and endLine to read a chunk of max 200 lines. Use GrepFile to get an outline (grep 'public') and find the line numbers.";
             }
 
-            return HashlineEncoder.Encode(lines, startLine, endLine);
+            string result = HashlineEncoder.Encode(lines, startLine, endLine);
+            OnFileRead?.Invoke(path);
+            return result;
         }
         catch (Exception ex)
         {