refactor(lsp): restructure lsp plugin controller architecture and simplify provider cache

- Replace LSPManager usage with LSPController integration
- Move UI access through lsp_controller.lsp_manager_ui
- Remove legacy ProviderResponseCache client management
- Simplify completion filtering and matcher handling
- Improve typing annotations and modernize union syntax
- Clean up unused imports and dead code
- Fix completion item parsing for insertText/textEdit fallbacks
- Add async-safe scrolling via GLib.idle_add

plugins/code/ui/lsp_manager/mixins/lsp_client_events_mixin.py

@@ -23,7 +23,7 @@ class LSPClientEventsMixin:
         uri        = f"file://{fpath}" if not fpath.startswith("file://") else fpath
         buffer     = event.file.buffer
         text       = buffer.get_text(*buffer.get_bounds())
-        self._last_active_language_id = lang_id
+        self.active_language_id = lang_id
 
         controller._lsp_did_open({
             "uri": uri,
@@ -54,7 +54,7 @@ class LSPClientEventsMixin:
         uri        = f"file://{fpath}" if not fpath.startswith("file://") else fpath
         buffer     = event.file.buffer
         text       = buffer.get_text(*buffer.get_bounds())
-        self._last_active_language_id = lang_id
+        self.active_language_id = lang_id
 
         controller._lsp_did_save({"uri": uri, "text": text})
 
@@ -71,7 +71,7 @@ class LSPClientEventsMixin:
         uri        = f"file://{fpath}" if not fpath.startswith("file://") else fpath
         buffer     = event.file.buffer
         text       = buffer.get_text(*buffer.get_bounds())
-        self._last_active_language_id = lang_id
+        self.active_language_id = lang_id
 
         controller._lsp_did_change({
             "uri": uri,
@@ -97,7 +97,7 @@ class LSPClientEventsMixin:
 
         controller = self.clients[lang_id]
         uri        = f"file://{fpath}" if not fpath.startswith("file://") else fpath
-        self._last_active_language_id = lang_id
+        self.active_language_id = lang_id
 
         controller._lsp_definition({
             "uri": uri,
@@ -116,7 +116,7 @@ class LSPClientEventsMixin:
 
         controller = self.clients[lang_id]
         uri        = f"file://{fpath}" if not fpath.startswith("file://") else fpath
-        self._last_active_language_id = lang_id
+        self.active_language_id = lang_id
 
         controller._lsp_completion({
             "uri": uri,

plugins/code/ui/lsp_manager/mixins/lsp_server_events_mixin.py

@@ -29,22 +29,25 @@ class LSPServerEventsMixin:
 
         self.matchers.clear()
         for item in items:
-            label = item.get("label", "")
-            if not label: continue
+            label = item.get("label")
+            if not label: return None
 
-            text = item.get("insertText")
-            if not text and "textEdit" in item:
-                text = item["textEdit"].get("newText", "")
+            text = (
+                item.get("insertText")
+                or item.get("textEdit", {}).get("newText")
+                or item.get("textEditText", "")
+                or label
+            )
 
-            info = ""
-            if "detail" in item:
-                info = item["detail"]
-            elif "documentation" in item:
-                doc = item["documentation"]
-                if isinstance(doc, dict):
-                    info = doc.get("value", "")
-                else:
-                    info = str(doc)
+            detail = item.get("detail")
+            doc    = item.get("documentation")
+
+            if detail:
+                info = detail
+            elif isinstance(doc, dict):
+                info = doc.get("value", "")
+            else:
+                info = str(doc) if doc else ""
 
             self.matchers[label] = {
                 "label": label,