[r266-tech]

Description

MarkdownParser.parse() raises AttributeError for targets such as [example](./linked.md#section\ncontinued): the outer pattern accepts the target, but the fragment/query splitter returns None. Preserve the original target in that case, so parsing continues and valid neighboring links still rewrite.

Human Involvement

• A human participated in the implementation or review loop
• This PR was generated entirely by AI agents without human participation in the loop

Related Issue

Fixes #7624. Independently reproduced fragment/query newline inputs. The real directory parser records the affected file as failed and keeps a healthy sibling; downstream server import failure was not verified.

Type of Change

• Bug fix (non-breaking change that fixes an issue)

Changes Made

Add the null check in the existing link owner and parameterize its existing public-parser contract test. No API, storage, or lifecycle contract changes.

Testing

macOS arm64, Python 3.14.10, pytest 9.0.2; isolated synthetic configuration and source SDK/bot paths. Published 0.5.3 native libraries were used for imports; no native service or model ran.

• Expanded contract test on unmodified 90f4edcede4c: 2 failed, 1 passed, both failures at m.group().

• .venv/bin/python -m pytest tests/parse/test_markdown_link_rewrite.py -q --no-cov: 46 passed.

• .venv/bin/python -m pytest tests/parse/test_markdown_apply_layout.py tests/parse/test_markdown_filename_collision.py tests/parse/test_markdown_no_split.py tests/parse/test_markdown_split_token_budget.py tests/parse/test_markdown_local_image_refs.py -q --no-cov: 34 passed.

• Temporary test_scripts/ probe: 24 real Markdown/directory parser scenarios with LocalParseOutputStore, covering split/no-split, LF/CRLF, crossing a fence, and plain/external controls. All source files emit with the original text and a rewritten valid link; no directory failed_files remain.

• Ruff lint/format on both changed paths and git diff --check: passed.

• .venv/bin/mypy --no-incremental openviking/parse/parsers/markdown.py tests/parse/test_markdown_link_rewrite.py: 2189 baseline / 2187 patched errors across imported modules; no new diagnostics after normalizing shifted lines. The two removed errors are the nullable m.group() accesses. Exact original files were checked via --shadow-file in the same environment.

• Regression coverage added to the existing contract

• Related tests passed locally

• Tested on macOS

Checklist

• Reviewed the full two-file diff
• Followed repository style

Additional Notes

Seven existing dependency/Pydantic warnings remain. The full suite, server import outcome, and other operating systems were not tested.