feat: add GDScript (Godot) as a supported language

[woolfi182]

Summary

Adds GDScript — the scripting language for the Godot Engine — as a fully supported language in code-review-graph. GDScript uses the tree-sitter-gdscript grammar, already shipped in tree-sitter-language-pack as gdscript.abi3.so, so no new dependencies are required. .gd files are now parsed end-to-end: classes, functions, extends parent-class imports, and method calls all land in the graph.

What changed

code_review_graph/parser.py

• Added ".gd": "gdscript" to EXTENSION_TO_LANGUAGE
• Added "gdscript": ["class_definition", "class_name_statement"] to _CLASS_TYPES — covers inner classes (class Name:) and the file-level class_name Name identity declaration
• Added "gdscript": ["function_definition"] to _FUNCTION_TYPES — covers func, static func, and annotated @onready func
• Added "gdscript": ["extends_statement"] to _IMPORT_TYPES — treats the parent class / script path as a hard import dependency
• Added "gdscript": ["call", "attribute_call"] to _CALL_TYPES — bare calls produce call; obj.method() is an attribute node whose right-hand side is an attribute_call
• Added a gdscript branch to _extract_import() that resolves extends Node (type → identifier), extends "res://path.gd" (string literal), and extends SomeClass.Nested (type node)

tests/test_multilang.py

• Added TestGDScriptParsing class with 10 unit tests covering: language detection, class_name extraction, inner-class extraction, top-level & inner-class function extraction, extends → IMPORTS_FROM edge, direct and attribute method calls, qualified-name resolution for same-file calls, and CONTAINS edge wiring for both the file and the inner class

tests/fixtures/sample.gd

• New fixture exercising extends Node, class_name, const preload(...), signal, @export / @onready annotations, inner class with its own method, bare calls, attribute calls, and static func

CHANGELOG.md

• Added GDScript entry under [Unreleased]

Node-type mapping

Semantic role	GDScript tree-sitter node types	Notes
_CLASS_TYPES	class_definition, class_name_statement	Inner class X: + file-level class_name X
_FUNCTION_TYPES	function_definition	Includes static func and annotated funcs
_IMPORT_TYPES	extends_statement	Parent class / script path as IMPORTS_FROM edge
_CALL_TYPES	call, attribute_call	attribute_call lives inside an attribute node for obj.method()

The generic _get_name() handler already covers GDScript — class_definition, class_name_statement, and function_definition all expose a child of type name — so no changes were needed to name extraction.

How to test

# Run the GDScript-specific tests
pytest tests/test_multilang.py::TestGDScriptParsing -v

# Run the full multilang + parser suite
pytest tests/test_multilang.py tests/test_parser.py -q

# Lint
ruff check code_review_graph/

Local run: 10 new tests pass, 234 parser/multilang tests pass in total, ruff clean.

Usage

# Any Godot project
code-review-graph build --full
code-review-graph status        # .gd files now appear in language breakdown

Example queries that now work on a Godot codebase:

• get_impact_radius_tool({target: "ItemsManager.add_main_grid_item"}) — blast radius before editing a manager method
• query_graph_tool({pattern: "callers_of", name: "_ready"}) — find every scene that overrides _ready
• semantic_search_nodes_tool({query: "merge two items"}) — locate the merge logic by concept

Known gaps / future work

• preload("res://x.gd") and load("res://x.gd") currently show up as CALLS edges with target preload / load. Promoting them to IMPORTS_FROM would require a bespoke _extract_gdscript_constructs hook (mirroring _extract_lua_constructs). Left out to keep this PR minimal.
• .tscn (scene) and .tres (resource) files carry real cross-file dependencies via [ext_resource path="..."], but they have no tree-sitter grammar. A follow-up PR can add a regex-based handler — same pattern as _parse_notebook / _parse_databricks_py_notebook.
• signal declarations are not modeled (no semantic role fits). They could be added as Type nodes later if signal-aware review becomes useful.

[woolfi182]

@tirth8205 Can you please review? This is a base PR that support the language and I will create a few more to cover sources and scenes files soon