Extract binder package from citation-evidence (EBIND-WP-0001)

Extracts citation-evidence/src/binder/ into this repo as the standalone
@citation-evidence/evidence-binder package: headless binding service +
in-memory link repo, active-state machine, the SharedContracts §7
rect-registry contract (registry, change pumps, hooks, SVG overlay), and
the target-neutral reference FormRenderer.

- toolchain mirrors sibling extracted repos (pnpm/tsc/vitest/eslint);
  imports rewritten from @shared/@engine aliases to the engine's
  @citation-evidence/engine package specifiers
- dependency boundary (engine + anchor only; no source/work/umbrella)
  enforced via eslint no-restricted-imports
- docs: extraction inventory + contract deltas, ADR-0001 (reference UI
  kept as supported exports), refreshed README/SCOPE/INTENT, populated
  capabilities index
- typecheck + lint green, 37 tests passing

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

docs/adr/ADR-0001-reference-ui-surface.md

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+# ADR-0001 — Binder-owned reference UI surface
+
+- Status: accepted
+- Date: 2026-07-08
+- Workplan: EBIND-WP-0001 (T05)
+
+## Context
+
+The extracted binder slice includes two small React components:
+
+- `FormRenderer.tsx` — renders a `FormSchema` as an evidence-backed form. Each
+  field registers itself with the rect registry under `kind="field"`, focuses a
+  target via the active-state machine, and shows a link-count chip. This is the
+  component that produces the `field` leg of the visual-guide triple.
+- `FieldDefinitionForm.tsx` — a shared label/type editor used by `FormRenderer`'s
+  add-field and edit-field flows.
+
+The architectural rule is that the binder is *form-friendly but target-neutral*:
+it must not depend on `citation-work` and must not assume any particular host
+application.
+
+## Decision
+
+**Keep both components as supported binder exports.**
+
+- `FormRenderer` is contractual: it is the reference implementation of the
+  "form field publishes a `field` rect and drives active-target focus" half of
+  the rect-registry contract (SharedContracts §7). Demoting it to an example
+  would leave the §7 field-side contract without an in-repo reference.
+- `FieldDefinitionForm` is retained as a supporting export because `FormRenderer`
+  depends on it directly; splitting them across the package/example boundary
+  would break that import.
+
+Both remain **target-neutral**: they operate purely on `FormSchema` /
+`EvidenceTarget` and the binder's own hooks. They take no dependency on
+`citation-work`, `evidence-source`, or the umbrella. The umbrella owns the
+*composition* (wiring `FormRenderer` to persistence, sidebars, and the viewer)
+in `citation-evidence/src/app/**`; the binder owns only the renderer itself.
+
+## Consequences
+
+- `src/index.ts` continues to export `FormRenderer` (and its
+  `FormSchema` / `FormFieldSchema` / `FormRendererProps` types); the umbrella
+  imports them unchanged after cutover.
+- The package surface stays "headless core + rect-registry contract + one
+  reference form renderer" rather than a broad UI kit. Future richer UI belongs
+  in host apps, not here.
+- If a later workplan needs a genuinely illustrative demo, it goes under an
+  `examples/` tree, not the package root, so the subsystem boundary stays sharp.

docs/extraction-inventory.md

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+# Extraction inventory & contract deltas (EBIND-WP-0001-T01)
+
+Locks the extraction boundary for pulling `citation-evidence/src/binder/` into
+this repository. Authority for the shared contracts remains the umbrella wiki
+(`../citation-evidence/wiki/SharedContracts.md`,
+`../citation-evidence/wiki/DependencyMap.md`) until the cutover is complete.
+
+## 1. Files that extract into this repo
+
+All of `citation-evidence/src/binder/` moves to `evidence-binder/src/`:
+
+| Concern | Files |
+| --- | --- |
+| Headless link repo | `repos/in-memory-links.ts`, `repos/index.ts` |
+| Binding service | `services/bindings.ts` (+ `.test.ts`), `services/index.ts` |
+| Active-state machine | `state/active.ts` (+ `.test.ts`), `state/index.ts` |
+| Provider composition | `BinderProvider.tsx` |
+| Visual guide (rect registry) | `visual-guide/rect-registry.ts` (+ `.test.ts`), `visual-guide/events.ts`, `visual-guide/react-hooks.ts` (+ `.dom.test.tsx`), `visual-guide/Overlay.tsx` (+ `.dom.test.tsx`), `visual-guide/index.ts` |
+| Reference UI | `FormRenderer.tsx` (+ `FormRenderer.dom.test.tsx`), `FieldDefinitionForm.tsx` |
+| Barrel | `index.ts` |
+
+The upstream `src/binder/README.md` is **not** carried over — this repo's
+top-level `README.md` supersedes it.
+
+## 2. Files that remain umbrella-only
+
+Everything that composes binder with the rest of the app stays in the umbrella
+(`citation-evidence/src/app/**`): `FormsApp.tsx`, `HighlightRectBridge.tsx`,
+`ActiveEvidenceChips.tsx`, `CaptureLinkPersister.tsx`, `capture-persistence.ts`,
+`App.tsx`. These are consumers of the binder, not part of it.
+
+## 3. Import-alias rewrite
+
+Upstream binder files used the umbrella's internal path aliases. On extraction
+they are rewritten to the engine's published package specifiers (the same
+convention `evidence-anchor` uses):
+
+| Upstream alias | Extracted specifier |
+| --- | --- |
+| `@shared/evidence-link`, `@shared/ids` | `@citation-evidence/engine/shared` |
+| `@engine/events` | `@citation-evidence/engine` |
+
+No source imported `@binder/*`, `@work/*`, `@source/*`, or `@app/*`, so no
+forbidden edge existed in the slice. The binder MVP slice imports **only** from
+`citation-engine` (shared types + event bus). It does not currently import
+`evidence-anchor`, which is an *allowed but unused* edge (DependencyMap §2).
+
+## 4. Contract deltas resolved
+
+- **`EvidenceTarget` naming / target vocabulary.** No drift. The engine's
+  `EvidenceTarget` (`{ targetType, targetId }`) and the closed
+  `EvidenceTargetType` catalogue (`form-field`, `claim`, `requirement`,
+  `decision`, `document-section`) are canonical and consumed as-is. The MVP only
+  exercises `form-field`. `INTENT.md` previously listed extra target kinds
+  ("tasks, or other information objects"); that is aspirational prose, not a
+  competing enum, and is left as narrative.
+- **Dropped relation values `derived-from` / `needs-check`.** These are **not**
+  members of the canonical `EvidenceRelation` enum (`supports`, `contradicts`,
+  `explains`, `qualifies`, `source-for`, `context-for`). The extracted package
+  does **not** reintroduce them; any earlier INTENT mention of them is dropped
+  from the implemented surface.
+- **Event vocabulary / removal semantics.** The binding service emits only
+  canonical bus events: `EvidenceLinkCreated`, `EvidenceLinkUpdated`,
+  `EvidenceLinkRemoved` (hard-delete; rejected-status path deferred), and
+  `EvidenceItemActivated` / `FormFieldActivated`. All are members of the engine's
+  `EngineEvent` union — no local event vocabulary is introduced.
+
+## 5. Forbidden dependency edges (called out before copy)
+
+Per DependencyMap §2, `evidence-binder` may depend on `citation-engine` and
+`evidence-anchor`, and must **not** depend on `evidence-source`,
+`citation-work`, or the umbrella `citation-evidence`. This boundary is enforced
+mechanically by `eslint.config.js` (`no-restricted-imports`).