0.4.3 --- Split Layouts, Installer Uninstaller & Install Log
=============================================================

*Released*

SplitView Widget
----------------

Allow the Host window's content area to be divided into multiple panes, each with its
own ``TabBar`` and ``TabManager``, with a draggable sash between panes. Two screens can
run side by side (or stacked) in a single window without spawning a ``DetachedWindow``.

- New ``SplitView`` widget (``VIStk/Widgets/_SplitView.py``) replaces the single
  ``TabManager`` in ``Host``
- Wraps a ``ttk.PanedWindow`` (horizontal or vertical); each slot is either a
  ``TabManager`` (leaf) or a nested ``SplitView`` (branch)
- Tree-of-panes model supports arbitrary split arrangements
- ``SplitView.split(pane, direction)`` --- replaces a ``TabManager`` leaf with a new
  ``SplitView`` containing the original pane and a fresh empty ``TabManager``; direction
  is ``"right"`` or ``"down"``
- ``SplitView.remove_pane(pane)`` --- collapses the parent ``SplitView``, promoting the
  surviving sibling; dissolves if root becomes a single ``TabManager``
- Sash positions default to 50/50; user can drag freely

Focused Pane
~~~~~~~~~~~~

- ``SplitView.focused_pane`` tracks the last-interacted pane
- Clicking a tab or content frame sets that pane as focused
- ``HostMenu`` and window title always reflect the focused pane's active tab
- Focus transfers to the nearest remaining pane when the focused pane is removed

Right-Click Split Actions
~~~~~~~~~~~~~~~~~~~~~~~~~

Two new entries in the ``TabBar`` right-click context menu:

- **Split right** --- horizontal split, tab moves to the new right pane
- **Split down** --- vertical split, tab moves to the new bottom pane

Pane Auto-Removal
~~~~~~~~~~~~~~~~~

- When a pane's tab count reaches zero, it calls ``on_pane_empty`` on its ``SplitView``
- The ``SplitView`` removes the empty pane and promotes the surviving sibling

Drag-to-Split
~~~~~~~~~~~~~~

- Dragging a tab into the outer 25% of any pane's content area shows a translucent blue
  overlay indicating the split direction (right, left, down, up)
- Dragging to the center shows a full-pane overlay; dropping there adds the tab to the
  pane without splitting
- If a pane has only one tab, dragging it over its own pane shows the center overlay
- Tab bar insertion indicator shown alongside center overlay to preview tab placement
- Parent sash positions preserved during nested splits

Cross-Window Drag-to-Split
~~~~~~~~~~~~~~~~~~~~~~~~~~~

- Drag-to-split works across Host and ``DetachedWindow`` in both directions
- ``DetachedWindow`` is now wrapped in ``SplitView`` with full split and focus support
- ``SplitView._registry`` enables cross-window zone detection
- Z-order aware: overlapping windows only show drop zones for the frontmost window at
  the cursor position (uses Tk ``wm stackorder``)
- Target window lifts to the front as the cursor enters its non-overlapping area

Focus-Aware Tab Styling
~~~~~~~~~~~~~~~~~~~~~~~~

- Active tab in the focused pane shown in brighter grey; unfocused panes are dimmer
- When a window loses OS focus, all pane focus indicators dim; restore on regain
- ``SplitView._global_focused_pane`` tracks the last-focused pane across all windows

Global Focus Tracking
~~~~~~~~~~~~~~~~~~~~~

- Clicking any widget inside a pane (buttons, entries, etc.) sets focus to that pane
  via a toplevel-level ``<Button-1>`` binding
- ``Host._open_tab()`` uses the globally focused pane, even from ``DetachedWindow``
- ``Host.open()`` raises the correct window (Host or DetachedWindow)

Menu Bar Fixes
~~~~~~~~~~~~~~

- ``HostMenu.set_screen_items()`` replaces shared cascades in-place when the label
  matches an existing shared cascade, preventing duplicate menus
- ``HostMenu.clear_screen_items()`` restores original shared cascade menus
- ``HostMenu.reset_overrides()`` called on tab deactivate

Host Changes
~~~~~~~~~~~~

- ``self.TabManager`` property returns ``self._split_view.focused_pane``
- ``host.open()`` opens new tabs into the globally focused pane (Host or DetachedWindow)
- ``host._get_all_tab_names()`` walks the full ``SplitView`` tree
- Activate/deactivate/menu/title callbacks wired to all panes
- ``_on_tab_split`` handles within-pane, cross-pane, center, and cross-window drops

DetachedWindow Changes
~~~~~~~~~~~~~~~~~~~~~~

- Content area now wrapped in ``SplitView`` (was bare ``TabManager``)
- ``tab_manager`` property returns ``_split_view.focused_pane``
- ``_on_tab_split`` mirrors Host implementation
- ``_on_close`` iterates all panes in the SplitView tree

TabBar Changes
~~~~~~~~~~~~~~

- ``on_tab_split: callable | None`` --- callback ``(name, direction, target_pane)``
- ``on_drag_zone: callable | None`` --- drag-to-split zone detection during motion
- Right-click menu gains "Split right" and "Split down"
- Focus-aware ``_tab_bg()`` returns different colours based on pane focus state

Uninstaller
-----------

- ``Release.release()`` generates an uninstaller executable alongside the installer
- Reads ``.VIS/install_log.json`` to know exactly which files and shortcuts were created
- Removes all installed binaries, adjacent files, and desktop shortcuts
- Optionally deregisters from Windows Add/Remove Programs

Install Log
-----------

- Installer writes ``.VIS/install_log.json`` after a successful install
- Records every extracted file path, every shortcut created, the install location, and a
  timestamp
- Used by the uninstaller and the update-in-place installer (0.4.4)
- Quiet mode (``--Quiet``) also writes the install log