fix(highlight): respect auto_focus toggle in workspace edit handler

[taigrr]

Problem

The workspace/applyEdit handler always opened and scrolled to edited files regardless of the auto_focus setting. When the user toggled auto-focus off via :CrushFocusOff or the API, the handler ignored this because:

1. highlight.lua had its own config copy set during setup() that was never updated when init.lua toggled auto_focus
2. ensure_buffer_visible() always opened new windows for off-screen buffers

Fix

Pass a callback from init.lua to highlight.lua that reads the live config.auto_focus state. This ensures the handler always sees the current toggle state.

When auto-focus is off:

• Edits are still applied normally
• Buffers already visible in a window still get flash highlights
• The handler no longer opens new windows or scrolls to the edit location

When auto-focus is on (default): behavior is unchanged.

Changes

• highlight.lua: Added auto_focus_check callback, is_auto_focus_enabled() helper, gated window-opening and scroll logic
• lsp.lua: Passes callback options through to highlight.setup()
• init.lua: Passes closure over live config.auto_focus when setting up LSP
• Tests: Added coverage for callback acceptance and state propagation

All 55 tests pass.