feat(8.0): brain.fillSubtypes migration helper + pre-RC1 gap closure

- brain.fillSubtypes(rules): idempotent subtype back-fill for pre-8.0 data.
  One rule per NounType/VerbType (literal default or per-entry function);
  fills only entries still missing a subtype through the public update()/
  updateRelation() paths; returns { scanned, filled, skipped, errors, byType }.
  Full unit suite in tests/unit/brainy/fill-subtypes.test.ts.
- Fix getNouns/getVerbs pagination hasMore (peek one past the window) —
  was permanently false, silently truncating every multi-page walk.
- find({ near }) without near.id now throws a teaching error instead of an
  opaque storage sharding failure; CLI --threshold without --near applies a
  plain score floor.
- CLI init/close audit: every one-shot command init()s, close()s, and exits
  explicitly; delete the unmaintained interactive REPL; replace the cloud-era
  storage subcommands with status/batch-delete; new types/validate commands.
- requireSubtype JSDoc now documents the 8.0 default-on contract; audit()
  recommendation points at fillSubtypes.
- Docs: data-storage-architecture rewritten to the real 8.0 on-disk layout;
  README storage section reflects filesystem+memory and snapshots; eli5 and
  SEMANTIC_VFS /as-of/ semantics corrected; internal tracker IDs and
  .strategy references scrubbed from published files.

src/graph/graphAdjacencyIndex.ts

@@ -766,8 +766,8 @@ export class GraphAdjacencyIndex implements GraphIndexProvider {
       // Note: LSM-trees will be recreated from storage via their own initialization
       // Verb data will be loaded on-demand via UnifiedCache
 
-      // Brainy 8.0: storage is always local (filesystem or memory) per
-      // BR-BRAINY-80-STORAGE-SIMPLIFY. Load all verbs at once.
+      // Brainy 8.0: storage is always local (filesystem or memory — the
+      // cloud adapters were removed). Load all verbs at once.
       const storageType = this.storage?.constructor.name || ''
       let totalVerbs = 0