fix(reads): the readiness gate guards every index read surface — serving empty from a not-ready provider is unrepresentable

A production store acked writes while readback served empty for fifteen
minutes. The brainy half: the lazy readiness gate had exactly one caller —
find() — while related() and every VFS path served straight from providers
that init had deferred (disableAutoRebuild on a large store). A false
health verdict from the accelerator pulled the trigger; the unguarded read
surfaces were the gun.

Every index read funnels through three helpers; the gate now lives at those
choke points, so any first read on a cold instance waits for the build and
then serves truth — the fast path after the latch is one boolean. The lazy
build's start is narrated through the production logger, never the
silent-suppressible console: fifteen silent minutes taught that line.

Pinned with the production shape: related() as the first-ever read on a
fresh lazy instance serves the relation; a filtered find serves the row.

src/brainy.ts

@@ -3907,6 +3907,12 @@ export class Brainy<T = any> implements BrainyInterface<T> {
     uuid: string,
     options?: { direction?: 'in' | 'out' | 'both'; limit?: number; offset?: number }
   ): Promise<string[]> {
+    // READ-SURFACE READINESS GATE (the 4.2.4 blackout's brainy half): every
+    // index read funnels through this helper, so the gate here makes
+    // serve-while-not-ready UNREPRESENTABLE — a production store once acked
+    // writes while every non-find() read served empty from a not-ready
+    // provider for 15 minutes. Fast path after the latch is one boolean.
+    await this.ensureIndexesLoaded()
     const entityInt = this.graphEntityInt(uuid)
     if (entityInt === undefined) return []
     const neighborInts = await this.graphIndex.getNeighbors(entityInt, options)
@@ -11807,6 +11813,12 @@ export class Brainy<T = any> implements BrainyInterface<T> {
     filter: unknown,
     opts?: { limit?: number; offset?: number }
   ): Promise<string[]> {
+    // READ-SURFACE READINESS GATE (the 4.2.4 blackout's brainy half): every
+    // index read funnels through this helper, so the gate here makes
+    // serve-while-not-ready UNREPRESENTABLE — a production store once acked
+    // writes while every non-find() read served empty from a not-ready
+    // provider for 15 minutes. Fast path after the latch is one boolean.
+    await this.ensureIndexesLoaded()
     try {
       return await this.metadataIndex.getIdsForFilter(filter, opts)
     } catch (err) {
@@ -14279,6 +14291,12 @@ export class Brainy<T = any> implements BrainyInterface<T> {
     verbTypes?: Set<VerbType>,
     limit?: number
   ): Promise<string[]> {
+    // READ-SURFACE READINESS GATE (the 4.2.4 blackout's brainy half): every
+    // index read funnels through this helper, so the gate here makes
+    // serve-while-not-ready UNREPRESENTABLE — a production store once acked
+    // writes while every non-find() read served empty from a not-ready
+    // provider for 15 minutes. Fast path after the latch is one boolean.
+    await this.ensureIndexesLoaded()
     // 8.0 BigInt boundary: unmapped node → no relations.
     const nodeInt = this.graphEntityInt(nodeId)
     if (nodeInt === undefined) return []
@@ -16217,7 +16235,15 @@ export class Brainy<T = any> implements BrainyInterface<T> {
       return
     }
 
-    // Start lazy rebuild (with mutex to prevent concurrent rebuilds)
+    // Start lazy rebuild (with mutex to prevent concurrent rebuilds).
+    // ALWAYS narrated (prodLog, never the silent-suppressible console): a
+    // read that triggers an index build must be visible to the operator —
+    // fifteen silent minutes of a production blackout taught this line.
+    prodLog.warn(
+      `[Brainy] first read on this instance is building the derived indexes ` +
+        `(deferred at open by disableAutoRebuild) — reads WAIT and then serve; ` +
+        `nothing serves empty. Bounded by store size; progress under [MetadataIndex]/[GraphIndex].`
+    )
     this.lazyRebuildInProgress = true
     this.lazyRebuildPromise = this.rebuildIndexesIfNeeded(true)
       .then(() => {