feat(files-media): group files by directory + add 'Add Directory' button

- render_files_and_media now wraps the per-file loop in directory groups
  via aggregate.group_files_by_dir + imscope.tree_node_ex (mirrors the
  Context Composition visual style at gui_2.py:3114)
- New 'Add Directory' button next to 'Add Files to Inventory':
  uses filedialog.askdirectory() + os.walk to bulk-import a folder tree
- Button IDs (i, add_f_{i}, rem_f_{i}) preserve global uniqueness via
  file_indices map (regression-safe across the directory wrap)
- Test uses mock button=False, mock filedialog.askopenfilenames/askdirectory
  to avoid opening a real Tk dialog during test run

src/gui_2.py

@@ -2701,36 +2701,41 @@ def render_files_and_media(app: App) -> None:
 
     to_remove_idx = -1
     app.files.sort(key=lambda f: f.path.lower() if hasattr(f, 'path') else str(f).lower())
-    for i, f_item in enumerate(app.files):
+    file_indices = {id(f): idx for idx, f in enumerate(app.files)}
-     imgui.table_next_row()
+    grouped = aggregate.group_files_by_dir(app.files)
-     imgui.table_set_column_index(0)
+    for dir_name, g_files in sorted(grouped.items()):
-     fpath = f_item.path if hasattr(f_item, 'path') else str(f_item)
+     with imscope.tree_node_ex(f"{dir_name}##files_dir", imgui.TreeNodeFlags_.default_open) as dir_open:
-     in_context = any((cf.path if hasattr(cf, 'path') else str(cf)) == fpath for cf in app.context_files)
+      if dir_open:
-     is_cached = any(fpath in c for c in getattr(app, '_cached_files', []))
+       for f_item in g_files:
+        i = file_indices[id(f_item)]
+        imgui.table_next_row()
+        imgui.table_set_column_index(0)
+        fpath = f_item.path if hasattr(f_item, 'path') else str(f_item)
+        in_context = any((cf.path if hasattr(cf, 'path') else str(cf)) == fpath for cf in app.context_files)
+        is_cached = any(fpath in c for c in getattr(app, '_cached_files', []))
 
-     if imgui.button(f"+##add_f_{i}"):
+        if imgui.button(f"+##add_f_{i}"):
-      if not in_context:
+         if not in_context:
-       from src import models
+          from src import models
-       new_item = models.FileItem(path=fpath)
+          new_item = models.FileItem(path=fpath)
-       app.context_files.append(new_item)
+          app.context_files.append(new_item)
-       app._populate_auto_slices(new_item)
+          app._populate_auto_slices(new_item)
-     
+        
-     imgui.same_line()
+        imgui.same_line()
-     if imgui.button(f"x##rem_f_{i}"):
+        if imgui.button(f"x##rem_f_{i}"):
-      to_remove_idx = i
+         to_remove_idx = i
 
-     imgui.table_set_column_index(1)
+        imgui.table_set_column_index(1)
-     imgui.text(fpath)
+        imgui.text(fpath)
-     if imgui.is_item_hovered(): imgui.set_tooltip(fpath)
+        if imgui.is_item_hovered(): imgui.set_tooltip(fpath)
-     
+        
-     imgui.table_set_column_index(2)
+        imgui.table_set_column_index(2)
-     if in_context:
+        if in_context:
-      imgui.text_colored(imgui.ImVec4(0.3, 0.8, 0.3, 1), "Active")
+         imgui.text_colored(imgui.ImVec4(0.3, 0.8, 0.3, 1), "Active")
-     elif is_cached:
+        elif is_cached:
-      imgui.text_colored(imgui.ImVec4(0.3, 0.8, 1, 1), "Cached")
+         imgui.text_colored(imgui.ImVec4(0.3, 0.8, 1, 1), "Cached")
-     else:
+        else:
-      imgui.text_disabled(" - ")
+         imgui.text_disabled(" - ")
-    
     imgui.end_table()
     if to_remove_idx != -1: app.files.pop(to_remove_idx)
   
@@ -2738,7 +2743,18 @@ def render_files_and_media(app: App) -> None:
   if imgui.button("Add Files to Inventory"):
    r = hide_tk_root(); paths = filedialog.askopenfilenames(); r.destroy()
    for p in paths:
-    if p not in [f.path if hasattr(f, 'path') else f for f in app.files]: app.files.append(models.FileItem(path=p))
+    if p not in [f.path if hasattr(f, "path") else f for f in app.files]: app.files.append(models.FileItem(path=p))
+  imgui.same_line()
+  if imgui.button("Add Directory"):
+   r = hide_tk_root(); dirpath = filedialog.askdirectory(); r.destroy()
+   if dirpath:
+    existing = {f.path if hasattr(f, "path") else str(f) for f in app.files}
+    for root, _dirs, files in os.walk(dirpath):
+     for fname in files:
+      full = os.path.join(root, fname)
+      if full not in existing:
+       app.files.append(models.FileItem(path=full))
+       existing.add(full)
  
  imgui.separator()
  if imgui.collapsing_header("Screenshots", imgui.TreeNodeFlags_.default_open):

tests/test_files_and_media_tree.py

@@ -0,0 +1,29 @@
+from unittest.mock import patch, MagicMock
+import os, tempfile
+from src import models
+from src.gui_2 import render_files_and_media
+
+def test_files_rendered_under_directory_grouping(app_instance):
+ with tempfile.TemporaryDirectory() as tmp:
+  sub = os.path.join(tmp, "sub")
+  os.makedirs(sub, exist_ok=True)
+  for p in [os.path.join(tmp, "a.py"), os.path.join(tmp, "b.py"), os.path.join(sub, "c.py")]:
+   open(p, "w").close()
+  app_instance.files = [models.FileItem(path=os.path.join(tmp, "a.py")), models.FileItem(path=os.path.join(tmp, "b.py")), models.FileItem(path=os.path.join(sub, "c.py"))]
+  with patch("src.gui_2.imgui") as mock_imgui, patch("src.gui_2.imscope") as mock_imscope, patch("src.gui_2.filedialog") as mock_filedialog, patch("src.gui_2.hide_tk_root", return_value=MagicMock()):
+   mock_imgui.collapsing_header.return_value = True
+   mock_imgui.TableFlags_ = type("T", (), {"resizable": 1, "borders": 2, "row_bg": 4})()
+   mock_imgui.TableColumnFlags_ = type("C", (), {"width_fixed": 1, "width_stretch": 2})()
+   mock_imgui.begin_table.return_value = True
+   mock_imgui.button.return_value = False
+   mock_imscope.group.return_value.__enter__.return_value = None
+   mock_imscope.tree_node_ex.return_value.__enter__.return_value = True
+   mock_filedialog.askopenfilenames.return_value = ()
+   mock_filedialog.askdirectory.return_value = ""
+   try:
+    render_files_and_media(app_instance)
+   except Exception as e:
+    import pytest
+    pytest.fail(f"render_files_and_media raised: {e}")
+  assert len(app_instance.files) == 3
+  assert mock_imscope.tree_node_ex.called, "render_files_and_media should group files under tree_node_ex by directory"