feat(tcloo): add document-local TclOO completions, signature help and hints

Add conservative, document-local TclOO type inference and tooling so the server
can offer method completions, signature help, and inlay parameter hints for
statically resolvable TclOO receivers (including `new`/`create`, `my`, and
simple return-chains). Also surface class names as completion items and emit
semantic tokens for class declarations/references.

Notable changes:
- New tcloo_* tools: completion, symbols, and argument parsing; integrated into
  on_completion, signature_help, inlay hint generation and semantic token
  highlighting. Completions are returned early when an OO receiver context is
  detected.
- Use a completion-friendly parser fallback when the main AST fails (TclSyntaxError)
  so editing-in-progress code still yields useful completions.
- Add CompletionItemKind.Class to command kinds, exclude class items from the
  poco completion name cache, and include new unit tests for the TclOO helpers.

server/src/lsp_tclserver.py

@@ -14,6 +14,7 @@ from tclint.lexer import TclSyntaxError
 from tclint.violations import Violation
 from tools import checks, parser
 from tools.completion_items import CompletionCollector
+from tools.tcloo_symbols import class_completion_items
 from tools.formatter import NxFormatter as Formatter
 from tools.inlay_hint import InlayHintSignature, build_custom_inlay_signatures
 from tools.navigation import FileSymbolIndex, build_file_symbol_index
@@ -190,6 +191,7 @@ class TclLanguageServer(LanguageServer):
                 item.label
                 for path_items in self.poco_completion.values()
                 for item in path_items
+                if item.kind != lsp.CompletionItemKind.Class
             )
             self._custom_function_names_cache = (self._index_generation, names)
             return names
@@ -542,6 +544,7 @@ class TclLanguageServer(LanguageServer):
                 else self.parse_source(document.source)
             )
             tree.accept(collector, recurse=True)
+            collector.custom_functions.extend(class_completion_items(tree))
             docs = build_proc_docs(tree, document.source)
             navigation_index = build_file_symbol_index(
                 filepath, document.uri, tree