PPF-2055: Make the documentation example checker fail on tool errors #2055

Version

Reviewed baseline: PyPDFForm 6.0.0, commit 0b5cc1dc8604b36693864852d76ed7e60f903451.

Issue Description

At the reviewed snapshot, run_pyright() returned None for invalid JSON and main() then returned normally after cleanup. The subprocess return code was not enforced, allowing checker failures to look like successful documentation validation.

Work

In scripts/doc_examples_type_check.py, enforce subprocess outcomes and reject malformed or missing Pyright JSON. Keep temporary-file cleanup in failure paths and distinguish diagnostics from an inability to run the checker.

Acceptance Criteria

• A missing executable, nonzero tool exit, malformed output, and reported type errors all fail the check with useful messages. Valid, clean output passes.

Basis and Dependencies

R13. Coordinates with E1-01; both the checker and its calling script must propagate failure.

Source and Validation

Action E1-02, Group 1 — Lowest-hanging fruit, from the October 10, 2026 action plan; supporting review evidence. Related action identifiers refer to that plan.

The behavior above is evidence from the source review, not a new reproduction performed when filing this issue. Reconfirm the relevant baseline or document intervening changes before implementation. Follow the plan's completion and validation rules and the Developer Guide, including meaningful regression assertions for behavior changes.