fix(hybrid): match bare "Page N" in failed-page error parser (#467)

* Fix: detect failed pages via error messages and gap detection union

Docling may include failed pages as empty entries in the pages dict,
making gap-only detection miss them. Add error message parsing
("Page N: <error>") and union both strategies so neither failure mode
is lost.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: i-Veni-Vidi-Vici <biuld1234@gmail.com>

* Fix: correct misleading docstring in missing pages key test

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: i-Veni-Vidi-Vici <biuld1234@gmail.com>

* Add: overlap dedup test for gap and error parsing union

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: i-Veni-Vidi-Vici <biuld1234@gmail.com>

* fix(hybrid): match bare "Page N" in failed-page error parser

Docling's StandardPdfPipeline emits "Page N: <error>" when an error
description is available, or a bare "Page N" with no colon when the
error description is empty (standard_pdf_pipeline.py: error_msg falsy
branch). The previous regex r"^Page\s+(\d+):" required a colon and
silently dropped the bare form.

Relax to r"^Page\s+(\d+)(?::|$)" so both forms extract the page number.
Defensive only: in the wrapper's current pipeline this branch is rare
because failed_pages always carry a non-empty RuntimeError message, but
the change costs nothing and protects against future docling/wrapper
changes (e.g. switch to PaginatedPipeline / VlmPipeline, or new error
paths that omit the description).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: i-Veni-Vidi-Vici <biuld1234@gmail.com>

---------

Signed-off-by: i-Veni-Vidi-Vici <biuld1234@gmail.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: i-Veni-Vidi-Vici

python/opendataloader-pdf/src/opendataloader_pdf/hybrid_server.py

@@ -118,7 +118,8 @@ def _extract_failed_pages_from_errors(errors: list[str]) -> list[int]:
     """Extract failed page numbers from error messages.
 
     Docling error messages follow the pattern "Page N: <error>" (e.g.,
-    "Page 26: std::bad_alloc"). Even when docling includes failed pages
+    "Page 26: std::bad_alloc") or, when no error description is available,
+    a bare "Page N" with no colon. Even when docling includes failed pages
     in the pages dict as empty entries, the error messages reliably
     indicate which pages actually failed.
 
@@ -129,7 +130,7 @@ def _extract_failed_pages_from_errors(errors: list[str]) -> list[int]:
         Sorted list of 1-indexed page numbers that failed.
     """
     failed = set()
-    page_pattern = re.compile(r"^Page\s+(\d+):")
+    page_pattern = re.compile(r"^Page\s+(\d+)(?::|$)")
     for msg in errors:
         m = page_pattern.match(msg)
         if m:

python/opendataloader-pdf/tests/test_hybrid_server_partial_success.py

@@ -207,6 +207,10 @@ def test_no_page_errors(self):
         ]
         assert _extract_failed_pages_from_errors(errors) == []
 
+    def test_bare_page_no_colon(self):
+        """Bare 'Page N' (no colon) should be matched when error_msg is empty."""
+        assert _extract_failed_pages_from_errors(["Page 26"]) == [26]
+
 
 class TestBuildConversionResponseErrorParsing:
     """Tests for failed page detection via error message parsing.