chore(8.0): final pre-RC1 sweep — API consistency, named errors, orphans, zero-cast codebase

docs/ADR-001-generational-mvcc.md

@@ -28,7 +28,7 @@ path and the native path.
 
 - A **monotonic u64 generation counter** is the store's logical clock. It
   advances once per committed `transact()` batch and once per
-  single-operation write (`add`/`update`/`delete`/`relate`/…), so
+  single-operation write (`add`/`update`/`remove`/`relate`/…), so
   `brain.generation()` is always a meaningful watermark. It is persisted in
   `_system/generation.json` and never reissued for anything durable.
 - `brain.now()` **pins** the current generation in O(1) and returns a `Db` —