Replace pyright with ty for type checking

AGENTS.md

@@ -2,7 +2,7 @@
 
 ## Project Overview
 
-A Cookiecutter template for Python packages, supporting both CLI and library project types. Generates projects with uv, ruff, pyright, and pytest pre-configured. It also comes with GitHub Actions workflows configured for the project.
+A Cookiecutter template for Python packages, supporting both CLI and library project types. Generates projects with uv, ruff, ty, and pytest pre-configured. It also comes with GitHub Actions workflows configured for the project.
 
 This template is opinionated and enforces recommended practices when creating new Python projects.
 

{{cookiecutter.project_slug}}/AGENTS.md

@@ -15,7 +15,7 @@ This is a Python library package.
 - Package manager: uv
 - Build backend: uv_build
 - Linting/formatting: ruff
-- Type checking: pyright
+- Type checking: ty
 - Testing: pytest
 - CI: GitHub Actions (lint, test, release{%- if cookiecutter.documentation != 'none' %}, docs{%- endif %})
 
@@ -24,7 +24,7 @@ This is a Python library package.
 Use Makefile targets, not tool commands directly:
 
 - `make format` - Fix formatting issues
-- `make lint` - Run all static checks (ruff, pyright)
+- `make lint` - Run all static checks (ruff, ty)
 - `make test` - Run tests with coverage
 - `make doc` - Generate documentation
 - `make build` - Build the package

{{cookiecutter.project_slug}}/Makefile

@@ -37,7 +37,7 @@ lint:
 	uv sync --group lint
 	uv run ruff format --check && \
 		uv run ruff check && \
-		uv run pyright{% if cookiecutter.docstring_coverage %} && \
+		uv run ty check{% if cookiecutter.docstring_coverage %} && \
 		uv run interrogate -c pyproject.toml .{% endif %}
 
 .PHONY: format

{{cookiecutter.project_slug}}/pyproject.toml

@@ -36,7 +36,7 @@ lint = [
     # NOTE: ruff is under active development, so we pin conservatively here
     # and let Dependabot periodically perform this update.
     "ruff ~= 0.14.0",
-    "pyright ~= 1.1",
+    "ty >=0.0.2",
     {%- if cookiecutter.docstring_coverage %}
     "interrogate",
     {%- endif %}
@@ -63,14 +63,11 @@ Source = "https://github.com/{{ cookiecutter.github_username }}/{{ cookiecutter.
 # don't attempt code coverage for the CLI entrypoints
 omit = ["{{ cookiecutter.__project_src_path }}/_cli.py"]
 
-[tool.pyright]
+[tool.ty.environment]
+python-version = "3.10"
+
+[tool.ty.src]
 include = ["src", "test"]
-pythonVersion = "3.10"
-typeCheckingMode = "strict"
-reportUnusedImport = "warning"
-reportUnusedVariable = "warning"
-reportGeneralTypeIssues = "error"
-reportMissingTypeStubs = true
 
 [tool.ruff]
 line-length = 100