Refactor LSP manager architecture and event + completion pipeline

- Replace legacy LSPManagerClient + LSPManagerUI with ClientManager and UIManager
- Remove WebsocketClient in favor of unified Websocket implementation
- Move LSP initialization config loading into centralized config module
- Update LSPClient to support dynamic socket, improved init params, and doc version tracking
- Introduce range-based didChange notifications and add implementation + references requests
- Expand LSPClientEvents to support implementation/references and structured range edits
- Simplify websocket response handling and normalize LSP response parsing flow
- Decouple UI from LSP manager core; UI now emits address/port for client creation
- Refactor completion provider pipeline:
  - Split TextChangedEvent into TextInsertedEvent and DeleteRangeEvent
  - Update ProviderResponseCacheBase and controller dispatch paths accordingly
- Improve SourceBuffer and SourceFile event tracking with delete-range support
- Update plugin system:
  - Centralize command/provider registration via helper methods
  - Add LSP commands: definition, references, implementation, toggle UI
- Enhance response handlers to support references and implementation hooks
- Improve Python LSP config (jedi completion, signatures, references enabled)
- Fix minor GTK lifecycle and buffer signal handling issues
- Clean up unused imports, dead code, and outdated JSON server configs

src/libs/dto/code/events/__init__.py

@@ -26,6 +26,7 @@ from .get_source_views_event import GetSourceViewsEvent
 from .create_command_system_event import CreateCommandSystemEvent
 from .request_completion_event import RequestCompletionEvent
 from .cursor_moved_event import CursorMovedEvent
+from .delete_range_event import DeleteRangeEvent
 from .modified_changed_event import ModifiedChangedEvent
 from .text_changed_event import TextChangedEvent
 from .text_inserted_event import TextInsertedEvent

src/libs/dto/code/events/delete_range_event.py

@@ -0,0 +1,19 @@
+# Python imports
+from dataclasses import dataclass, field
+
+# Lib imports
+import gi
+
+gi.require_version('Gtk', '3.0')
+
+from gi.repository import Gtk
+
+# Application imports
+from .code_event import CodeEvent
+
+
+
+@dataclass
+class DeleteRangeEvent(CodeEvent):
+    start: Gtk.TextIter = None
+    end: Gtk.TextIter   = None

src/libs/dto/code/events/unregister_provider_event.py

@@ -1,7 +1,11 @@
 # Python imports
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 
 # Lib imports
+import gi
+gi.require_version('GtkSource', '4')
+
+from gi.repository import GtkSource
 
 # Application imports
 from .code_event import CodeEvent
@@ -10,4 +14,6 @@ from .code_event import CodeEvent
 
 @dataclass
 class UnregisterProviderEvent(CodeEvent):
-    provider_name: str = ""
+    provider_name: str                     = ""
+    provider: GtkSource.CompletionProvider = None
+    language_ids: list                     = field(default_factory=lambda: [])