feat(entity): Chunk #4 remaining items — consistency UI, context rail, palette search, expanded seed & DATA_MODEL

- Consistency tab in EntitiesView surfacing findInconsistencies() results
- ContextRail + MentionPopover wired into WritingView for entity context/hover
- CommandPalette indexes entities and chapters for cross-entity search
- link field type for entity references in character fields
- findDeadCharacterMentions consistency check + tests
- Expand seed with a location, note, and a natural Elias Vell mention so the
  dead-character-after-death case is actually exercised
- Author docs/DATA_MODEL.md documenting core schemas, types, storage contract
- Rename CharacterMention id attr -> entityId to match core backlinks/consistency

packages/editor/src/mention.ts

@@ -103,7 +103,7 @@ export const MentionAutocomplete = Extension.create({
           const nodeType = schema.nodes[CHARACTER_MENTION];
           if (!nodeType) return false;
 
-          const mention = nodeType.create({ id, label });
+          const mention = nodeType.create({ entityId: id, label });
           const tr = state.tr.deleteRange(atPos, from).insert(atPos, mention);
           editor.view.dispatch(tr);
           return true;

packages/editor/src/nodes/CharacterMention.tsx

@@ -3,7 +3,7 @@ import { CHARACTER_MENTION, colorAttribute } from "../constants.js";
 
 /**
  * Character mention — an inline atom linking to a character entity.
- * Attributes: `id` (character id) and `label` (display name). Inline in HTML
+ * Attributes: `entityId` (character id) and `label` (display name). Inline in HTML
  * as `<span class="mention mention-character" data-id="...">@Name</span>`.
  */
 export const CharacterMention = Node.create({
@@ -14,11 +14,11 @@ export const CharacterMention = Node.create({
 
   addAttributes() {
     return {
-      id: {
+      entityId: {
         default: null,
         isRequired: true,
         parseHTML: (element) => element.getAttribute("data-id"),
-        renderHTML: (attributes) => ({ "data-id": attributes.id }),
+        renderHTML: (attributes) => ({ "data-id": attributes.entityId }),
       },
       label: {
         default: "",
@@ -36,9 +36,9 @@ export const CharacterMention = Node.create({
   renderHTML({ node }) {
     return [
       "span",
-      { class: "mention mention-character", "data-id": node.attrs.id, "data-label": node.attrs.label },
+      { class: "mention mention-character", "data-id": node.attrs.entityId, "data-label": node.attrs.label },
       "@",
-      node.attrs.label ?? node.attrs.id,
+      node.attrs.label ?? node.attrs.entityId,
     ];
   },
 });