fixes several live-preview and crop-mode edge cases and adds a few related UI improvements

ChangeLog.md

@@ -8,7 +8,11 @@ Todo: More testing Linux / Mac. Create Windows .exe. Write better documentation
 - `l` now runs quick auto-levels, `L` runs auto white balance plus auto-levels, `A` runs quick auto white balance, `-` lowers highlights/whites in 14-point steps, `_` raises whites in 14-point steps, and `=` keeps pushing shadows in 7-point steps inside that live session.
 - Crop and editor edits now keep accumulating in memory on the current image instead of forcing an immediate save or backup churn.
 - The live session is persisted once when you navigate away, start a drag, explicitly save, or quit, so preview stays responsive while drag-out and navigation still get the latest pixels.
-- Updated README/help text and kept the version at 1.6.3.
+- Fixes crop preview behavior so committed crops continue to display correctly when zooming.
+- Adds `+` as the inverse shadow/blacks adjustment for quick auto-adjust.
+- Fixes the Actions → Sort submenu behavior by using a popup instead of a sibling menu.
+- Adds `--loupe` startup mode for faster launch into single-image view on large folders.
+- Updates README shortcut and command-line documentation.
 
 ## 1.6.2 (2026-03-28)
 

README.md

@@ -17,7 +17,7 @@ This tool is optimized for speed, using `libjpeg-turbo` for decoding, aggressive
 - **Instant Navigation:** Sub-10ms next/previous image switching, high performance decoding via `PyTurboJPEG`.
 - **Image Editor:** Built-in editor with exposure, contrast, white balance, sharpness, and more (E key)
 - **Background Darkening:** Mask-based background darkening tool (K key) with smart edge detection, subject protection, and multiple modes. Paint rough background hints and the tool refines them into natural-looking dark backgrounds.
-- **Quick Auto Adjust:** Press `l` for quick auto-levels, `L` for auto white balance + auto-levels together, `A` for auto white balance, `-`/`_` to keep adjusting the highlight/white side in 14-point steps, and `=` to deepen the shadow side in 7-point steps. These update the live in-memory edit session immediately and save once when you navigate away, start a drag, or explicitly save.
+- **Quick Auto Adjust:** Press `l` for quick auto-levels, `L` for auto white balance + auto-levels together, `A` for auto white balance, `-`/`_` to keep adjusting the highlight/white side in 14-point steps, and `=`/`+` to adjust the shadow/black side in 7-point steps. These update the live in-memory edit session immediately and save once when you navigate away, start a drag, or explicitly save.
 - **Photoshop / Gimp Integration:** Edit current image in Photoshop or Gimp (P key) - always uses RAW files when available.
 - **Clipboard Support:** Copy image path to clipboard (Ctrl+C)
 - **Image Filtering:** Filter images by filename
@@ -58,6 +58,7 @@ FastStack performs best on Python 3.12 due to PySide6 compatibility.
 4.  **Run:**
     ```bash
     faststack
+    faststack --loupe /path/to/photos  # start in loupe view, skip initial thumbnails
     ```
 
 ### Windows / Linux
@@ -68,6 +69,31 @@ pip install .
 faststack
 ```
 
+Start directly in single-image loupe view when you want faster startup on large
+folders and do not need the thumbnail grid immediately:
+
+```bash
+faststack --loupe "C:\path\to\photos"
+```
+
+### Command Line Options
+
+```text
+faststack [options] [image_dir]
+python -m faststack.app [options] [image_dir]
+```
+
+- `image_dir`: Optional directory of images to open. If omitted, FastStack uses
+  the configured default directory or prompts for one.
+- `--loupe`: Start directly in single-image loupe view and skip the initial
+  thumbnail grid refresh for faster startup on large folders.
+- `--debug`: Enable verbose debug logging and timing information.
+- `--debugcache`: Enable cache telemetry/debug output.
+- `--debug-thumbtiming`: Enable thumbnail pipeline timing logs. Implies
+  `--debug`.
+- `--debug-thumbtrace`: Enable detailed thumbnail pipeline trace logs. Implies
+  `--debug`.
+
 ### Windows Performance Note
 On Windows, `PyTurboJPEG` also needs the native `libjpeg-turbo` library (`turbojpeg.dll`).
 
@@ -144,6 +170,7 @@ If you do nothing, FastStack will still run, but JPEG decoding and thumbnail gen
 - `L`: Quick auto white balance + auto levels (live session; saved on navigation, drag, or Ctrl+S)
 - `-`: Darken the current auto-adjust highlights/whites by 14 points in the live session
 - `_`: Raise the current auto-adjust whites by 14 points in the live session
+- `+`: Raise the current auto-adjust shadows/blacks by 7 points in the live session
 - `=`: Deepen the current auto-adjust shadows/background by 7 points in the live session
 - `E`: Toggle Image Editor
 - `Esc`: Close active dialog, editor, cancel crop, or exit fullscreen