feat: Complete plugin lifecycle management with lazy loading and runtime reload

Major changes:
- Add unload() method to all plugins for proper cleanup (unregister commands/providers/LSP clients, destroy widgets, clear state)
- Implement lazy widget loading via "show" signal across all containers
- Add autoload: false manifest option for manual/conditional plugin loading
- Add Plugins UI with runtime load/unload toggle via Ctrl+Shift+p
- Implement controller unregistration system with proper signal disconnection
- Add new events: UnregisterCommandEvent, GetFilesEvent, GetSourceViewsEvent, TogglePluginsUiEvent
- Fix signal leaks by tracking and disconnecting handlers in widgets (search/replace, LSP manager, tabs, telescope, markdown preview)
- Add Save/Save As to tabs context menu
- Improve search/replace behavior (selection handling, focus management)
- Add telescope file initialization from existing loaded files
- Refactor plugin reload watcher to dynamically add/remove plugins on filesystem changes
- Add new plugins: file_history, extend_source_view_menu, godot_lsp_client
- Fix bug in prettify_json (undefined variable reference)

TODO.md

@@ -0,0 +1,22 @@
+___
+### Add
+1. Add Godot LSP Client
+1. Add Collapsable code blocks
+1. Add Plugin to <Shift\><Ctrl\>| and <Ctrl\>| to split views up, down, left, right
+1. Add <Ctrl\>i to **lsp_manager** to list who implements xyz
+
+___
+### Change
+1. Make **telescope** plugin a generic base to allow query mode additions through plugins
+1. Make **lsp_manager** hard coded values configurable, plus add fields to UI
+___
+### Fix
+- Fix **telescope** search selection when items hidden such that
+       hidden items don't get selected on up/down key
+- Fix to make acive tab on **tabs_bar** scroll to center
+- Fix **file_state_watcher** to prompt refrsh if external changes applied
+- Fix on lsp client unload to close files lsp side and unload server endpoint
+- Fix multi-select <Shift\><Ctrl\> left/right block select movement de-sync
+       from leader when '_' in word
+
+___