lint markdown recursively

`scan *.md` only matched the repository root, so a file added under any
subdirectory would have stopped being checked without the CI step noticing.
Scanning recursively follows the files instead of the layout, and
--respect-gitignore keeps it off .venv and .dora.

.github/workflows/validate.yml

@@ -63,7 +63,7 @@ jobs:
 
       - run: uv run ruff check .
 
-      - run: uv run pymarkdown scan *.md
+      - run: uv run pymarkdown scan -r --respect-gitignore .
 
       - run: uv run pytest -q
 

AGENTS.md

@@ -8,7 +8,7 @@ Rules for AI coding assistants working in this repository.
   `uv run ruff check .`, `uv run python ...`. Never `pip` into the ambient
   environment.
 - **`ruff` is the linter and the formatter.** `uv run ruff check .` must be clean.
-- **Markdown is linted too.** `uv run pymarkdown scan *.md` must be clean. Its line
+- **Markdown is linted too.** `uv run pymarkdown scan -r --respect-gitignore .` must be clean. Its line
   length is set in `pyproject.toml`.
 - **numpy-style docstrings.**
 - **Dependencies must ship prebuilt wheels for linux-x86_64, linux-aarch64 and