V3 Python type-check capability pack. By-value connector composition (service_kind=cli, no separate ingredient): one local mypy CLI ingredient exposes bounded project operations for readiness and Python type-check diagnostics. Type checks run from an explicit project directory cwd supplied at execution time, inspect one trusted Python file or directory, and return plain diagnostics via the python.type_check catalog operation. Fixed-function and reproducible: ignores discovered project config, ignores missing third-party imports, disables incremental cache reads, disables cache writes on Unix-like hosts, disables color and summary noise, no daemon, no command/eval string, no module/package selector, no caller-supplied config/plugin/cache path, no install/stubgen/stubtest, no arbitrary mypy flags, no shell wrapper, and no network egress. Type errors are represented as successful text findings; real invocation failures still fail. Requires mypy on PATH. Local and no-egress.