Add node_rename, complex node_set_property values, and script_patch

[dsarno]

Summary

• node_rename — rename nodes with sibling-collision and invalid-char validation via String.validate_node_name(). Undoable. NodePath/script references in other nodes are not auto-updated (documented in the tool).
• Complex node_set_property — coerces Resource (res:// path string or empty-string-to-clear), NodePath, StringName, Array, and Dictionary; _serialize_value recurses so typed round-trips stay JSON-safe.
• script_patch — anchor-based old_text → new_text replace with ambiguity detection and optional replace_all. Picked over line-range (fragile under drift) and unified diff (whitespace-sensitive) after a focused spike.

Closes the remaining High-Leverage Authoring items in docs/implementation-plan.md Phase 3 and makes the script.patch decision.

Test plan

• ruff check src/ tests/ passes
• pytest -v — 282 passing (+3 new unit/integration)
• GDScript test_run — 216 passing (+23 new: 7 rename, 8 complex set_property, 8 patch)
• Live smoke against running editor: rename (5 paths), set_property (Resource assign/clear/not-found, NodePath, float), script_patch (unique match, not-found, ambiguous, replace_all, file-not-found)

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[Copilot]

Pull request overview

Adds new authoring capabilities to the Godot AI MCP surface: node renaming, richer node property setting (including Resources/NodePath/containers), and an anchor-based script patch tool.

Changes:

• Introduce node_rename tool/handler wired through Python runtime ↔ Godot plugin, with undo support and validation.
• Extend node_set_property coercion/serialization to support Resource path assignment/clearing, NodePath, StringName, Array, and Dictionary.
• Add script_patch tool/handler for exact-substring replacement with ambiguity detection and optional replace_all, plus tests and plan-doc updates.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/unit/test_runtime_handlers.py	Extends stub runtime + unit tests for node_rename and script_patch handlers.
tests/integration/test_mcp_tools.py	Adds MCP integration coverage for node_rename and script_patch tool calls.
test_project/tests/test_script.gd	Adds Godot-side tests validating patch_script behavior and error cases.
test_project/tests/test_node.gd	Adds Godot-side tests for resource/nodepath coercion, serialization recursion, and rename behaviors.
test_project/tests/_mcp_test_script.gd	Adds a placeholder script fixture used by the test scene setup.
src/godot_ai/tools/script.py	Exposes new script_patch MCP tool with user-facing documentation.
src/godot_ai/tools/node.py	Updates node_set_property typing/docs and adds node_rename MCP tool.
src/godot_ai/handlers/script.py	Adds Python shared handler script_patch sending patch_script command.
src/godot_ai/handlers/node.py	Adds Python shared handler node_rename sending rename_node command.
plugin/addons/godot_ai/plugin.gd	Registers rename_node and patch_script commands with the dispatcher.
plugin/addons/godot_ai/handlers/script_handler.gd	Implements patch_script file editing logic + response shape.
plugin/addons/godot_ai/handlers/node_handler.gd	Implements rename_node, enhances set_property coercion and recursive serialization.
docs/implementation-plan.md	Marks Phase 3 items complete and updates test-count totals.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

patch_script allows patching any res:// file type, but the tool/docstring frames this as a GDScript (.gd) operation. Unlike create_script (which enforces .gd), this can accidentally rewrite non-text/binary assets (e.g., .tscn/.tres) as UTF-8 text and corrupt them. Add the same .gd extension validation (or otherwise restrict to safe text/script extensions) before reading/writing.

[Copilot]

patch_script checks for missing new_text but not missing old_text. If the caller omits old_text, the handler returns old_text must not be empty rather than a consistent Missing required param: old_text, and it also prevents explicitly passing an empty string (even if that might be useful for no-op validation). Consider adding an explicit "old_text" in params check (mirroring new_text) and keep the non-empty constraint as a separate validation.

Suggested change

	return McpErrorCodes.make(McpErrorCodes.INVALID_PARAMS, "Missing required param: new_text")
	return McpErrorCodes.make(McpErrorCodes.INVALID_PARAMS, "Missing required param: new_text")
	if not "old_text" in params:
	return McpErrorCodes.make(McpErrorCodes.INVALID_PARAMS, "Missing required param: old_text")

[Copilot]

The node_set_property docstring says Resources can be cleared with null only, but the Godot-side implementation also treats an empty string ("") as a signal to clear Resource properties. Either document the empty-string behavior here (since clients may rely on it) or remove that behavior for a single, consistent clearing mechanism.