8.0 RC cleanup toward "one place per thing, zero-config, no deprecation":
- Remove the `brain.neural()` clustering namespace (ImprovedNeuralAPI + the dead
legacy NeuralAPI + the neural CLI + neural-only types). Similarity is `find({vector})`
/ `similar({to})`; attribute grouping is the aggregation `GROUP BY` engine. The separate
entity-extraction / smart-import feature (NeuralImport, NeuralEntityExtractor, SmartExtractor,
NaturalLanguageProcessor, `brain.extract()`/`brain.nlp()`) is kept.
- Remove `Db.search()`; `find()` is the one query verb (accepts a bare string or FindParams).
Fix the bundled MCP client, which called a non-existent `brain.search(query, limit)` →
now `find({ query, limit })`.
- Storage config: collapse to one canonical top-level `path` key. The pre-8.0 aliases
(`rootDirectory`, `options.*`, `fileSystemStorage.*`) are removed and now THROW with the
exact rename instead of silently defaulting to `./brainy-data` on upgrade. A single resolver
feeds createStorage, the 7.x→8.0 migration probe, and the plugin-factory handoff, so a native
storage provider resolves the identical root (no split-brain).
- Fix `similar({ threshold })`: the min-similarity filter was silently dropped; it is now
applied as a post-filter on `result.score` (the documented way to bound semantic results).
- Fix `vfs.rename()` on a directory: child path updates spread the entity vector into `update()`
and failed dimension validation; they are metadata-only updates now.
- Fix `vfs.move()`: copy+delete orphaned the content-addressed content blob (the destination
shared the source hash, then unlink removed it). `move()` now delegates to `rename()` — an
in-place path change that preserves the blob and the entity id, for files and directories.
- Fix streaming import: the bulk fast path never flushed mid-import nor signalled queryability.
Entity writes are now chunked by a progressive flush interval (100 → 1000 → 5000); each chunk
flushes and emits `progress.queryable`, so imported data is queryable during the import.
- Sweep all docs, comments, and JSDoc for the removed/changed APIs.
Integration suite: 49 files / 588 passed / 0 failed. Unit: 80 files / 1456 passed, no type errors.
7.x stored every object branch-scoped under branches/<branch>/<basePath>; 8.0
stores the IDENTICAL entity structure at the storage ROOT plus the generational
_system/_generations layer. GenerationStore.open tolerates a missing manifest
(opens at gen 0), so a naive 8.0 open of a 7.x directory reported ZERO entities
and SILENTLY LOST ALL DATA. The fix is blocked in the normal init order — cor 3.0's
storage-factory legacy guard fires inside setupStorage(), five steps before the
old migration check — so a new phase runs BEFORE setupStorage().
legacyLayoutMigrationPhase() (init, between loadPlugins and setupStorage):
- Fast-path: returns immediately when there's no top-level branches/ dir (every
native 8.0 brain + fresh dir pays only one fs.existsSync on the init hot path).
- Runs on a temporary BUILT-IN FileSystemStorage (never the plugin adapter, whose
guard would throw). Memory/cloud/pre-built-adapter stores are a strict no-op.
- Detect via _system/migration-layout.json marker + branches/<head>/entities/.
- autoMigrate:false on a legacy layout THROWS explicit guidance (no silent loss).
- Acquire the writer lock, then COLLAPSE branches/<head>/entities/* → entities/*
via the .gz-transparent raw primitives (read→write→delete, idempotent/resume-safe;
NOT fs.rename — logical paths + memory-adapter incompatibility).
- Rebuild persisted counts (rebuildCounts → totalNounCount/counts.json;
rebuildTypeCounts/rebuildSubtypeCounts → per-type stats) — the three indexes are
rebuilt by the normal init's rebuildIndexesIfNeeded afterward.
- Finalize: stamp the flat-v8 marker (re-open no-op), drain the head branch
(non-head branches = 7.x version history 8.0's MVCC does not import; left as-is).
Tests (tests/integration/migration-7x-to-8x.test.ts): the data-loss LOCK (a
built-in FileSystemStorage on a reshaped 7.x dir reports 0 nouns), a byte-equal
ROUND TRIP (find/related/counts equal the pre-reshape reference), IDEMPOTENCY,
the autoMigrate:false GUARD throw, and the native-flat NO-OP. RELEASES upgrade
checklist rewritten (the old note documented the opposite, lossy behavior).
1477 unit + migration 5 + db-mvcc 25 green; no init-path regression.
Follow-ups (hardening, not correctness for the common case): backupTo config
plumbing (currently a loud warning), a crash-mid-collapse resume test, and a
boundary-safe fake-plugin ordering test.
