feat(entity): Chunk #4 data layer + entity UI (characters & world-building)

Data layer:
- Fuzzy scorer (packages/core/src/fuzzy.ts) with index recovery + unit tests
- Backlink computation (packages/core/src/backlinks.ts) incl. entity-level backlinks
- Consistency checker (packages/core/src/consistency.ts) incl. reciprocity/scope + unit tests
- StorageAdapter contract extended with listEntities/searchEntities/saveEntity/deleteEntity;
  implemented in Local (Dexie) and Server adapters; contract tests cover entity CRUD + ?q= search
- WorldItem.fields now supports list values (keyPeople, rivals); expanded RelationshipKind
- @mention autocomplete extension + picker in the editor package

Entity UI (apps/web/src/features/entities/):
- Generic field renderer (EntityFields) driven by ENTITY_FIELDS/FieldDef
- Tabbed directory with fuzzy search + entity cards (EntitiesView)
- Create/edit/delete drawer (EntityEditor) reusing shared fields
- Relationship editor + force-directed SVG relationship map
- Entity engine stylesheet; wired into nav

Store: project-store entity methods (load/create/update/delete) over the StorageAdapter contract.

CI-green: typecheck, lint, 65 tests, and web build all pass.

PLAN.md

@@ -270,7 +270,7 @@ Each chunk is a 1–3 day work order in `CHUNK#n.md`, written so a human *or* a
 | 1 | **Scaffold & Foundations** | 1 | ✅ Done | Monorepo, strict TS, tooling, app shell, theme system, CI, settings store |
 | 2 | **Data Model, Storage & Auth** | 3 | ⬜ Not started | Full domain types, StorageAdapter, Local + Server adapters, Fastify auth/multi-tenant, autosave, contract tests |
 | 3 | **Writing Surface** | 3 | 🟡 In progress | TipTap editor ✅, document tree ✅, focus mode ✅, Markdown I/O ✅, autosave ✅, writing view wired to storage adapter ✅ (UI-disappears crash fixed), fonts/logo polish 🟡 |
-| 4 | **Characters & World-Building** | 2 | ⬜ Not started | Entity schema, character sheets, world items, search, mentions, backlinks |
+| 4 | **Characters & World-Building** | 2 | 🟡 In progress | Entity schema ✅, character sheets ✅, world items ✅, fuzzy search ✅, mentions ✅, backlinks ✅, entity UI (sheets/search/relationships/map) ✅; pending: consistency UI, palette search, context rail, seed extension, DATA_MODEL.md, E2E |
 | 5 | **Plot & Whiteboard** | 3 | ⬜ Not started | Beat board + templates, timeline, React Flow whiteboard (200-node perf) |
 | 6 | **Export Pipeline** | 3 | ⬜ Not started | MD/HTML/EPUB/DOCX/ODT + PDF, export dialog, CI validation |
 | 7 | **Spell & Grammar** | 2 | ⬜ Not started | hunspell-WASM spellcheck, LanguageTool grammar, decorations + panel |
@@ -281,7 +281,7 @@ Each chunk is a 1–3 day work order in `CHUNK#n.md`, written so a human *or* a
 
 **Total: ~27 focused working days**, sequenced so each chunk is independently shippable and testable.
 
-**Progress:** 1 of 11 chunks complete. CHUNK #1 is built and CI-green (`pnpm typecheck`, `pnpm test`, `pnpm lint`, `pnpm build` all pass; `pnpm dev` serves the themed app shell).
+**Progress:** 1 of 11 chunks complete. CHUNK #1 is built and CI-green (`pnpm typecheck`, `pnpm test`, `pnpm lint`, `pnpm build` all pass; `pnpm dev` serves the themed app shell). CHUNK #2 and #3 are committed and CI-green. CHUNK #4 is in progress — its data layer (entity schema, fuzzy search, backlinks, consistency check, `@mention` autocomplete) and entity UI layer (character/world sheets, fuzzy search, relationship editor + map) are built and green, with a few items remaining (consistency UI wiring, palette search, context rail, seed extension, `docs/DATA_MODEL.md`, E2E).
 
 ---
 
@@ -298,4 +298,4 @@ Each chunk is a 1–3 day work order in `CHUNK#n.md`, written so a human *or* a
 
 ---
 
-*CHUNK #1 is complete. Next: read `CHUNK#2.md` and start executing. Each chunk's acceptance criteria are the gate to the next.*
+*CHUNK #1–#3 are complete and CI-green. Currently executing CHUNK #4 (Characters & World-Building). Each chunk's acceptance criteria are the gate to the next.*