test(8.0): Tier-1 integration via deterministic embedder (suite runnable again)

The integration suite loaded the real WASM model for every test, so a full run
took ~hours and reliably aborted (vitest reporter timeout) — which is why it was
never gated and silently rotted. Brainy already separates the embedder from all
other logic, so running integration with a deterministic embedder keeps every
code path real (HNSW build+search, graph traversal, metadata filtering,
transactions, storage/sharding, VFS, aggregation, import) while making the suite
complete in ~2 min on ANY machine — no GPU, no 16 GB requirement.

- Add isDeterministicEmbedMode() — a single source of truth for the test-embedder
  switch (BRAINY_DETERMINISTIC_EMBEDDINGS, plus the legacy BRAINY_UNIT_TEST alias),
  used by EmbeddingManager (init/embed/embedBatch) and brainy's eager-init guard.
- setup-integration.ts opts into it: Tier 1 = functional end-to-end. Real-model
  semantic quality + the real embedding pipeline move to a Tier-2 suite.

Full integration now runs 482 passing / 583 in ~2 min (was un-completable). The
remaining failures are pre-existing test rot, fixed next. Unit 1414 green.

src/brainy.ts

@@ -116,6 +116,7 @@ import { resolveJsHnswConfig, DEFAULT_RECALL } from './utils/recallPreset.js'
 import * as fs from 'node:fs'
 import { Db, type DbHost, type HistoricalQueryHandle } from './db/db.js'
 import { GenerationStore } from './db/generationStore.js'
+import { isDeterministicEmbedMode } from './embeddings/deterministicEmbedMode.js'
 import { GenerationConflictError } from './db/errors.js'
 import { MemoryStorage } from './storage/adapters/memoryStorage.js'
 import type {
@@ -885,9 +886,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
       //
       // `eagerEmbeddings: false` is the explicit override to force lazy init
       // (first-embed) even when this instance is the active embedder.
-      const isUnitTestMode =
-        process.env.BRAINY_UNIT_TEST === 'true' ||
-        (globalThis as { __BRAINY_UNIT_TEST__?: boolean }).__BRAINY_UNIT_TEST__ === true
+      const isUnitTestMode = isDeterministicEmbedMode()
       const eager = this.config.eagerEmbeddings ?? true
       if (
         eager &&

src/embeddings/EmbeddingManager.ts

@@ -14,6 +14,7 @@
 
 import { Vector, EmbeddingFunction } from '../coreTypes.js'
 import { WASMEmbeddingEngine } from './wasm/index.js'
+import { isDeterministicEmbedMode } from './deterministicEmbedMode.js'
 
 declare global {
   /**
@@ -77,9 +78,7 @@ export class EmbeddingManager {
    */
   async init(): Promise<void> {
     // In unit test mode, skip real model initialization
-    const isTestMode =
-      process.env.BRAINY_UNIT_TEST === 'true' ||
-      globalThis.__BRAINY_UNIT_TEST__
+    const isTestMode = isDeterministicEmbedMode()
 
     if (isTestMode) {
       // Production safeguard
@@ -151,9 +150,7 @@ export class EmbeddingManager {
    */
   async embed(text: string | string[] | Record<string, unknown>): Promise<Vector> {
     // Check for unit test environment
-    const isTestMode =
-      process.env.BRAINY_UNIT_TEST === 'true' ||
-      globalThis.__BRAINY_UNIT_TEST__
+    const isTestMode = isDeterministicEmbedMode()
 
     if (isTestMode) {
       if (process.env.NODE_ENV === 'production') {
@@ -233,9 +230,7 @@ export class EmbeddingManager {
   async embedBatch(texts: string[], options?: { signal?: AbortSignal }): Promise<number[][]> {
     if (texts.length === 0) return []
 
-    const isTestMode =
-      process.env.BRAINY_UNIT_TEST === 'true' ||
-      globalThis.__BRAINY_UNIT_TEST__
+    const isTestMode = isDeterministicEmbedMode()
 
     if (isTestMode) {
       if (process.env.NODE_ENV === 'production') {

src/embeddings/deterministicEmbedMode.ts

@@ -0,0 +1,39 @@
+/**
+ * @module embeddings/deterministicEmbedMode
+ * @description Single source of truth for "use deterministic test embeddings".
+ *
+ * Brainy's embedding model is a real WASM transformer — correct, but slow on CPU
+ * (a forward pass per text). For TEST tiers that exercise database *logic* (HNSW
+ * build + search, graph traversal, metadata filtering, transactions, storage,
+ * VFS, find composition), the embedding's semantic *quality* is irrelevant; only
+ * a deterministic, content-derived vector is needed. Switching the embedder to a
+ * deterministic stand-in keeps every other code path real while turning a
+ * multi-hour suite into a sub-minute, gateable one. Semantic quality and the
+ * real embedding pipeline are covered separately by the real-model test tier.
+ *
+ * This flag is honored ONLY outside production: {@link EmbeddingManager} throws
+ * if it is set while `NODE_ENV=production` (mock vectors in prod is a security
+ * risk). Enabled by env var or global so test setup files can opt in per tier.
+ */
+
+interface DeterministicEmbedGlobals {
+  __BRAINY_DETERMINISTIC_EMBED__?: boolean
+  /** Legacy alias — the original unit-test-only spelling. */
+  __BRAINY_UNIT_TEST__?: boolean
+}
+
+/**
+ * @description Whether the deterministic test embedder should be used instead of
+ * the real WASM model. True when `BRAINY_DETERMINISTIC_EMBEDDINGS=true` or the
+ * legacy `BRAINY_UNIT_TEST=true` env var is set, or the matching global is set.
+ * @returns `true` to use deterministic embeddings, `false` for the real model.
+ */
+export function isDeterministicEmbedMode(): boolean {
+  const g = globalThis as DeterministicEmbedGlobals
+  return (
+    process.env.BRAINY_DETERMINISTIC_EMBEDDINGS === 'true' ||
+    process.env.BRAINY_UNIT_TEST === 'true' ||
+    g.__BRAINY_DETERMINISTIC_EMBED__ === true ||
+    g.__BRAINY_UNIT_TEST__ === true
+  )
+}

tests/setup-integration.ts

@@ -1,60 +1,44 @@
 /**
- * Integration Test Setup - REAL AI functionality
+ * Integration Test Setup — Tier 1: Functional end-to-end (deterministic embedder)
  *
- * This setup enables real AI models for integration testing
- * Requires high memory environment (16GB+ RAM)
+ * These tests exercise every real code path — HNSW build + search, graph
+ * traversal, metadata filtering, triple-intelligence composition, MVCC
+ * transactions, sharding/persistence, VFS, aggregation, import — but with a
+ * DETERMINISTIC embedder instead of the real WASM transformer. The embedding's
+ * semantic *quality* is irrelevant to these assertions (which are structural:
+ * counts, ids, relationships, self-retrieval, transaction outcomes); making the
+ * vector deterministic turns a multi-hour, un-completable suite into a sub-minute
+ * one that any contributor can run on any machine, no GPU or 16 GB required.
+ *
+ * Semantic relevance + the real embedding pipeline are covered separately by the
+ * Tier-2 semantic suite (`tests/semantic/`, real model) — see
+ * `tests/configs/vitest.semantic.config.ts`.
  */
 
-beforeAll(async () => {
-  console.log('🤖 Integration Test Environment: Using REAL AI models')
-  console.log('⚠️  Requires 16GB+ RAM - this is normal for AI testing')
+beforeAll(() => {
+  console.log('🧪 Integration (Tier 1): deterministic embedder, all other code paths real')
 
-  // Set up environment for real AI testing
-  process.env.BRAINY_INTEGRATION_TEST = 'true'
-  process.env.BRAINY_MODELS_PATH = './models'
-  process.env.BRAINY_ALLOW_REMOTE_MODELS = 'false'  // Use local models only
+  // Deterministic embeddings — see src/embeddings/deterministicEmbedMode.ts.
+  process.env.BRAINY_DETERMINISTIC_EMBEDDINGS = 'true'
+  ;(globalThis as { __BRAINY_DETERMINISTIC_EMBED__?: boolean }).__BRAINY_DETERMINISTIC_EMBED__ = true
 
-  // Set memory limits and optimizations
-  process.env.ORT_DISABLE_MEMORY_ARENA = '1'
-  process.env.ORT_DISABLE_MEMORY_PATTERN = '1'
-  process.env.ORT_INTRA_OP_NUM_THREADS = '2'
-  process.env.ORT_INTER_OP_NUM_THREADS = '2'
+  // Marker retained for any test that branches on the integration environment.
+  ;(globalThis as { __BRAINY_INTEGRATION_TEST__?: boolean }).__BRAINY_INTEGRATION_TEST__ = true
+})
 
-  // Mark as integration test environment
-  ;(globalThis as any).__BRAINY_INTEGRATION_TEST__ = true
+afterAll(() => {
+  delete process.env.BRAINY_DETERMINISTIC_EMBEDDINGS
+  delete (globalThis as { __BRAINY_DETERMINISTIC_EMBED__?: boolean }).__BRAINY_DETERMINISTIC_EMBED__
+  delete (globalThis as { __BRAINY_INTEGRATION_TEST__?: boolean }).__BRAINY_INTEGRATION_TEST__
+})
 
-  // Check memory availability
-  const availableMemoryGB = process.env.NODE_OPTIONS?.includes('max-old-space-size')
-    ? parseInt(process.env.NODE_OPTIONS.match(/--max-old-space-size=(\d+)/)?.[1] || '0') / 1024
-    : 4
-  
-  console.log(`📊 Node.js heap limit: ${availableMemoryGB.toFixed(1)}GB`)
-  
-  if (availableMemoryGB < 8) {
-    console.warn('⚠️  WARNING: Less than 8GB allocated for integration tests')
-    console.warn('   Recommended: NODE_OPTIONS="--max-old-space-size=16384"')
-    console.warn('   Tests may fail due to insufficient memory')
-  }
-}, 60000) // 1 minute timeout for setup
-
-afterAll(async () => {
-  // Clean up
-  delete process.env.BRAINY_INTEGRATION_TEST
-  delete (globalThis as any).__BRAINY_INTEGRATION_TEST__
-  
-  // Force garbage collection if available
-  if (global.gc) {
-    global.gc()
-  }
-}, 30000) // 30 second timeout for cleanup
-
-// Utility function to skip tests if not enough memory
-export function requiresMemory(minGB: number) {
-  const availableMemoryGB = process.env.NODE_OPTIONS?.includes('max-old-space-size')
-    ? parseInt(process.env.NODE_OPTIONS.match(/--max-old-space-size=(\d+)/)?.[1] || '0') / 1024
-    : 4
-  
-  if (availableMemoryGB < minGB) {
-    throw new Error(`Test requires ${minGB}GB memory, only ${availableMemoryGB.toFixed(1)}GB allocated`)
-  }
+/**
+ * No-op retained for back-compat. Tier-1 integration tests use the deterministic
+ * embedder, so the real model's 16 GB requirement no longer applies — there is
+ * nothing to gate on. (Real-model memory cost lives in the Tier-2 semantic suite.)
+ *
+ * @param _minGB - Ignored.
+ */
+export function requiresMemory(_minGB: number): void {
+  // Intentionally empty — see the doc comment above.
 }