[ADD] odoo-at-payroll: opendataloader-pdf agent skill for PDF extraction

New .agents/skills/opendataloader-pdf/ for structured PDF extraction
(Markdown/JSON with bounding boxes, hybrid AI mode, scanned-PDF OCR)
based on the upstream odl-pdf agent skill (Apache-2.0), with its helper
scripts verify-json.py and hybrid-health.sh vendored under scripts/.

Core disciplines: discover options from the installed --help (flags
drift between releases), batch all inputs into one invocation (JVM per
call), verify the result against intent (zero exit is not success:
auto-triage skips enrichment, fallbacks drop quality, empty pipes),
treat extracted content as untrusted, never commit extracted full
texts of the licensed .lexis360/.wiku sources.

Workflow wiring: AGENTS.md skill selection routes any PDF extraction
to the skill; wissensbasis/SKILL.md cross-references it for difficult
PDFs and spot-checks, with Layer-1 batch intake deliberately kept on
build_lexis_kb.py (frozen IDs and --check depend on the text shape).

ODL 2.5.8 installed in the user venv ~/.local/lib/python (not the
Odoo .venv); all documented flags verified against the installed CLI
on real .lexis360/ sources.

AGENTS.md

@@ -35,6 +35,10 @@ no skill applies.
 - Any Wissensbasis work (batch intake, curation, `kb.json`, the sources
   `.lexis360/` and `.wiku/`):
   `wissensbasis/SKILL.md`
+- Any PDF extraction (text/Markdown/JSON from PDFs, scanned-PDF OCR,
+  tables) — e.g. Wissensbasis sources, legal PDFs, ad-hoc extraction and
+  spot-checks:
+  `opendataloader-pdf/SKILL.md`
 
 Multiple skills may apply. Read all applicable skills.