feat(pdf): extract standalone PDF ingest package (ESRC-WP-0001)

Bootstrap evidence-source from the citation-evidence src/source PDF slice.

- Headless core (src/pdf): ingest/extract/fingerprint, importing domain
  contracts from @citation-evidence/engine/shared (no local copies)
- Browser upload helpers isolated under src/browser behind a ./browser
  entry point, with an eslint boundary keeping the core browser-free
- pnpm/TS/vitest/eslint scaffold; 52 tests (contract + determinism)
- Fixtures resolved from the sibling citation-evidence checkout, not
  duplicated (real PII) — see docs/ADR-0002; suites skip when absent
- Boundary + fixture decisions recorded as docs/ADR-0001 / ADR-0002
- README/SCOPE rewritten; capability.infotech.pdf-evidence-ingest
  registered, NO_CAPABILITIES removed
- Follow-on workplans ESRC-WP-0002..0004 queued; ESRC-WP-0001 finished

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

workplans/ESRC-WP-0001-bootstrap-standalone-source-repo.md

@@ -4,7 +4,7 @@ type: workplan
 title: "Bootstrap standalone source repo from citation-evidence PDF slice"
 domain: infotech
 repo: evidence-source
-status: ready
+status: finished
 owner: codex
 topic_slug: citation_evidence_mvp
 created: "2026-06-21"
@@ -64,7 +64,7 @@ T01 extraction boundary and import plan
 
 ```task
 id: ESRC-WP-0001-T01
-status: todo
+status: done
 priority: high
 ```
 
@@ -93,7 +93,7 @@ the extraction relies on copying `citation-engine` shared types locally.
 
 ```task
 id: ESRC-WP-0001-T02
-status: todo
+status: done
 priority: high
 ```
 
@@ -119,7 +119,7 @@ runtime host.
 
 ```task
 id: ESRC-WP-0001-T03
-status: todo
+status: done
 priority: high
 ```
 
@@ -147,7 +147,7 @@ Acceptance: a consumer can pass PDF bytes to this repo and receive a valid
 
 ```task
 id: ESRC-WP-0001-T04
-status: todo
+status: done
 priority: high
 ```
 
@@ -176,7 +176,7 @@ browser/session-only behavior after extraction.
 
 ```task
 id: ESRC-WP-0001-T05
-status: todo
+status: done
 priority: high
 ```
 
@@ -203,7 +203,7 @@ source-to-anchor round-trip remains an umbrella integration test.
 
 ```task
 id: ESRC-WP-0001-T06
-status: todo
+status: done
 priority: high
 ```
 
@@ -227,7 +227,7 @@ package rather than the local `src/source/` copy for the PDF slice.
 
 ```task
 id: ESRC-WP-0001-T07
-status: todo
+status: done
 priority: medium
 ```
 

workplans/ESRC-WP-0002-html-markdown-representations.md

@@ -0,0 +1,55 @@
+---
+id: ESRC-WP-0002
+type: workplan
+title: "HTML and Markdown source representations"
+domain: infotech
+repo: evidence-source
+status: proposed
+owner: codex
+topic_slug: citation_evidence_mvp
+created: "2026-07-08"
+updated: "2026-07-08"
+spec_refs:
+  - README.md
+  - docs/ADR-0001-extraction-boundary.md
+  - ../citation-engine/src/shared/document.ts
+---
+
+# ESRC-WP-0002 — HTML and Markdown source representations
+
+The PDF slice (ESRC-WP-0001) established the ingest boundary and contract shape.
+This workplan extends ingest to HTML and Markdown sources, producing the same
+`{ document, representation }` pair over engine-owned contracts.
+
+## Open questions
+
+- Which `representationType` values do HTML/MD map to, and do they need new
+  `DocumentRepresentation` fields in `citation-engine`?
+- How is canonical text + offset map derived for reflowable formats that have
+  no fixed pages? (Page map may be empty or synthetic.)
+
+## Sketch
+
+```task
+id: ESRC-WP-0002-T01
+status: todo
+priority: medium
+```
+Define the HTML/MD representation contract with `citation-engine`; agree
+`representationType` and any offset/page semantics for pageless formats.
+
+```task
+id: ESRC-WP-0002-T02
+status: todo
+priority: medium
+```
+Implement `ingestHtml` / `ingestMarkdown` in `src/html/` and `src/markdown/`,
+reusing `fingerprintBytes` and the canonical-text normalizer.
+
+```task
+id: ESRC-WP-0002-T03
+status: todo
+priority: medium
+```
+Add fixture-driven contract tests mirroring the PDF suite; decide fixture
+ownership per ADR-0002.

workplans/ESRC-WP-0003-metadata-enrichment.md

@@ -0,0 +1,48 @@
+---
+id: ESRC-WP-0003
+type: workplan
+title: "Document metadata enrichment beyond pass-through options"
+domain: infotech
+repo: evidence-source
+status: proposed
+owner: codex
+topic_slug: citation_evidence_mvp
+created: "2026-07-08"
+updated: "2026-07-08"
+spec_refs:
+  - README.md
+  - src/pdf/ingest.ts
+---
+
+# ESRC-WP-0003 — Metadata enrichment
+
+Today `ingestPdf` only passes through caller-supplied `title`/`uri`/`metadata`.
+This workplan extracts intrinsic document metadata (PDF info dictionary,
+embedded XMP, page-derived signals like author/creation date/title) and folds
+it into the `Document` record without breaking the pure-over-bytes contract.
+
+## Sketch
+
+```task
+id: ESRC-WP-0003-T01
+status: todo
+priority: low
+```
+Enumerate available PDF metadata sources (info dict, XMP) via PDF.js and decide
+precedence vs. caller-supplied options (caller wins).
+
+```task
+id: ESRC-WP-0003-T02
+status: todo
+priority: low
+```
+Implement extraction into a normalized metadata shape; keep it optional so
+minimal-metadata PDFs still ingest cleanly.
+
+```task
+id: ESRC-WP-0003-T03
+status: todo
+priority: low
+```
+Contract tests over the fixture corpus asserting extracted vs. overridden
+metadata precedence.

workplans/ESRC-WP-0004-citation-recovery.md

@@ -0,0 +1,47 @@
+---
+id: ESRC-WP-0004
+type: workplan
+title: "Local citation recovery and external source discovery hooks"
+domain: infotech
+repo: evidence-source
+status: proposed
+owner: codex
+topic_slug: citation_evidence_mvp
+created: "2026-07-08"
+updated: "2026-07-08"
+spec_refs:
+  - INTENT.md
+  - README.md
+---
+
+# ESRC-WP-0004 — Citation recovery and source discovery hooks
+
+`evidence-source`'s original intent includes recovering citations when a stored
+selector goes stale and discovering the external source a document was drawn
+from. This is the largest deferred strand and depends on the anchoring layer's
+selector model.
+
+## Open questions
+
+- What is the recovery contract — does this repo *detect* stale selectors, or
+  only provide the re-ingest/re-fingerprint primitives the anchor layer calls?
+- Where does external source discovery (URL/DOI resolution) belong relative to
+  `citation-engine` and the umbrella?
+
+## Sketch
+
+```task
+id: ESRC-WP-0004-T01
+status: todo
+priority: low
+```
+Design the recovery boundary with the anchor layer: define what
+`evidence-source` owns vs. what stays in anchoring.
+
+```task
+id: ESRC-WP-0004-T02
+status: todo
+priority: low
+```
+Prototype re-ingest/re-fingerprint recovery primitives and a discovery hook
+interface (no network coupling baked into the core).