feat(sparkctl): add PDF extraction contract fixture

.agents/skills/pdf-extraction-contracts/SKILL.md

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+# Skill: PDF Extraction Contracts
+
+## Purpose
+
+Guide work on `PDF-EXTRACTION-V1` structured-data artifacts for SPARK-like administrative workflows.
+
+## Use This Skill When
+
+- Adding or reviewing PDF extraction fixtures.
+- Updating `schemas/spark/pdf_extraction_v1.schema.json`.
+- Validating external or manual extraction JSON before evidence packaging.
+- Connecting PDF extraction artifacts to Context Pack or Evidence Packet workflows.
+
+## Contract Boundary
+
+`PDF-EXTRACTION-V1` is an adapter contract. It accepts structured JSON from manual or external extraction tools as input evidence.
+
+It does not:
+
+- implement OCR
+- parse PDFs
+- download source PDFs
+- call providers
+- create a Codex plugin bundle
+- create an MCP server
+- create hooks or commands
+- claim official OpenAI plugin compatibility
+- claim official SPARK compatibility
+- replace human review
+
+## Required Fields
+
+Every artifact must include:
+
+- `schema_version`
+- `source_file`
+- `document_type`
+- `pages`
+- `tables`
+- `figures`
+- `extracted_fields`
+- `warnings`
+- `tool_metadata`
+
+`schema_version` must be `PDF-EXTRACTION-V1`.
+
+`tool_metadata.converter` must be one of:
+
+- `manual`
+- `docling`
+- `mineru`
+- `marker`
+- `pdftotext`
+- `other`
+
+`tool_metadata.extraction_mode` must be one of:
+
+- `synthetic_fixture`
+- `manual_fixture`
+- `external_tool`
+
+## Fixture Rules
+
+Synthetic fixtures must not include protected personal data, real SPARK data, real Daimler data, real medical data, or real ePA data.
+
+Do not commit source PDFs unless a future task explicitly approves that artifact and license boundary.
+
+## Validation
+
+Prefer local runtime validation with `validate_pdf_extraction_contract_value` and deterministic canonical hashing with the existing `canonical_json` and `sha256_hex` helpers.
+
+Report Agent Governor gate states using exactly one of:
+
+- `pass`
+- `fail`
+- `not_applicable`
+- `deferred`
+
+Use `not_applicable` only when a gate does not apply, and explain why. Use `deferred` when the gate is required but intentionally left for later human/tool review.
+
+For Rust changes, run:
+
+- `cargo fmt --all --check`
+- `cargo test`
+- `cargo clippy --all-targets --all-features -- -D warnings`
+
+## Claim Boundaries
+
+Use bounded wording: adapter contract, structured input evidence, manual fixture, external-tool output, review input, artifact manifest.
+
+Do not claim production readiness, compliance or certification, legal evidentiary status, forensic certainty, official SPARK compatibility, official OpenAI plugin compatibility, autonomous approval, or guaranteed correctness.