Implement ESRC-WP-0002/0003/0004: HTML/MD ingest, metadata, recovery

Add ingestHtml and ingestMarkdown with ADR-0003 pageless offset semantics,
PDF intrinsic metadata extraction with caller-wins merge (WP-0003), and
citation recovery primitives including re-ingest reconcile, local quote
search, and pluggable discovery hooks (ADR-0004). Mark all three workplans
finished with contract tests (80 passing).

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

@@ -4,14 +4,15 @@ type: workplan
 title: "HTML and Markdown source representations"
 domain: infotech
 repo: evidence-source
-status: proposed
+status: finished
 owner: codex
 topic_slug: citation_evidence_mvp
 created: "2026-07-08"
-updated: "2026-07-08"
+updated: "2026-07-09"
 spec_refs:
   - README.md
   - docs/ADR-0001-extraction-boundary.md
+  - docs/ADR-0003-html-markdown-representation.md
   - ../citation-engine/src/shared/document.ts
 state_hub_workstream_id: "c0d28886-e02f-4df2-abb6-ebe179171c94"
 ---
@@ -22,18 +23,19 @@ 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
+## Decisions (ADR-0003)
 
-- 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.)
+- HTML maps to `representationType: "html-dom"`; Markdown to
+  `"markdown-rendered"`.
+- Pageless formats omit `pageMap`; `offsetMap` is a single synthetic page-1
+  range covering `[0, canonicalText.length)`.
+- Inline fixtures owned by this repo (no PII); PDF corpus rules unchanged.
 
 ## Sketch
 
 ```task
 id: ESRC-WP-0002-T01
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "bf1d2a2f-41b4-44b5-b1d1-4f0eec5fbf59"
 ```
@@ -42,7 +44,7 @@ Define the HTML/MD representation contract with `citation-engine`; agree
 
 ```task
 id: ESRC-WP-0002-T02
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "66320911-a4b2-404f-b025-8b23dc0c9680"
 ```
@@ -51,9 +53,9 @@ reusing `fingerprintBytes` and the canonical-text normalizer.
 
 ```task
 id: ESRC-WP-0002-T03
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "266d168c-d93e-4387-9527-70aa0d5b2a6b"
 ```
 Add fixture-driven contract tests mirroring the PDF suite; decide fixture
-ownership per ADR-0002.
+ownership per ADR-0002.