docs, coverage: Add internal classes to function coverage checks

- Updated `AGENTS.md` to specify that underscore-prefixed methods in key
  client-facing classes (`_FilesClient`, `_AsyncFilesClient`) are in scope
  for function coverage checks.
- Expanded `DEFAULT_COVERAGE_CLASSES` in `noxfile.py` to include the
  files client classes.
- Updated `test-and-publish.yml` CI workflow to cover the files client
  classes.

Assisted-by: Codex

Author: datalogics-kam

.github/workflows/test-and-publish.yml

@@ -59,6 +59,8 @@ jobs:
           coverage/py${{ matrix.python-version }}/coverage.json
           --class PdfRestClient
           --class AsyncPdfRestClient
+          --class _FilesClient
+          --class _AsyncFilesClient
           --fail-under 90
           --markdown-report coverage/py${{ matrix.python-version }}/class-function-coverage.md
       - name: Upload coverage reports

AGENTS.md

@@ -146,6 +146,12 @@
   Optional payload branches (`pages`, `output`, `rgb_color`, etc.) need explicit
   coverage so serialization regressions are caught.
 
+- **Class function coverage scope:** The class coverage gate targets the main
+  client-facing classes (`PdfRestClient`, `AsyncPdfRestClient`, `_FilesClient`,
+  `_AsyncFilesClient`). For these classes, underscore-prefixed methods are
+  intentionally in scope and should be covered as part of the interface
+  contract.
+
 - Write pytest tests: files named `test_*.py`, test functions `test_*`, fixtures
   in `conftest.py` where shared.
 

noxfile.py

@@ -17,7 +17,12 @@
 PROJECT_ROOT = Path(__file__).resolve().parent
 DEFAULT_EXAMPLE_PYTHON = "3.11"
 EXAMPLES_DIR = PROJECT_ROOT / "examples"
-DEFAULT_COVERAGE_CLASSES = ("PdfRestClient", "AsyncPdfRestClient")
+DEFAULT_COVERAGE_CLASSES = (
+    "PdfRestClient",
+    "AsyncPdfRestClient",
+    "_FilesClient",
+    "_AsyncFilesClient",
+)
 
 
 def _install_test_dependencies(session: nox.Session) -> None: