Merge branch 'release/8.10.1'

# Conflicts:
#	.forgejo/workflows/ci.yml

src/brainy.ts

@@ -65,7 +65,8 @@ import type {
   OpaqueIdSet,
   AtGenerationVectors,
   VectorIndexProvider,
-  GraphIndexProvider
+  GraphIndexProvider,
+  ProviderMaintenanceDebt
 } from './plugin.js'
 import type {
   BrainyPlugin,
@@ -424,6 +425,30 @@ export interface WarmReport {
   totalDurationMs: number
 }
 
+/**
+ * @description Result of {@link Brainy.maintenanceDebt}: one outcome per
+ * index surface, mirroring {@link WarmReport}'s shape.
+ * - `'reported'` — the active provider for this surface implements
+ *   `maintenanceDebt?()` and its {@link ProviderMaintenanceDebt} payload is
+ *   attached verbatim under `debt`.
+ * - `'unavailable'` — the active provider does not implement the hook, so
+ *   nothing is known; brainy never estimates or infers a payload on its
+ *   behalf.
+ */
+export type MaintenanceDebtOutcome = 'reported' | 'unavailable'
+
+/**
+ * @description Per-surface result of {@link Brainy.maintenanceDebt}. Brainy
+ * performs no thresholding, polling, or estimation over this data — it is a
+ * pure passthrough of each active provider's own self-report (the provider
+ * owns the numbers; the operator owns the policy).
+ */
+export interface MaintenanceDebtReport {
+  vector: { outcome: MaintenanceDebtOutcome; debt?: ProviderMaintenanceDebt }
+  metadata: { outcome: MaintenanceDebtOutcome; debt?: ProviderMaintenanceDebt }
+  graph: { outcome: MaintenanceDebtOutcome; debt?: ProviderMaintenanceDebt }
+}
+
 /**
  * How long a failed aggregation-backfill walk suppresses fresh walk attempts.
  * Within the window, queries rethrow the recorded failure instantly (loud,
@@ -14352,9 +14377,16 @@ export class Brainy<T = any> implements BrainyInterface<T> {
    *   *some* backing storage as a side effect but is reported honestly as
    *   `'probed'`, never `'warmed'`. An empty index or unknown dimension has
    *   nothing to probe (`'unavailable'`).
-   * - **Metadata**: full hydration — every persisted field's sparse index is
-   *   loaded from storage (`MetadataIndexManager.hydrateAll()`), not just the
-   *   heuristic common-fields subset `init()` warms.
+   * - **Metadata**: calls the provider's own `warm?()` when the active
+   *   `'metadataIndex'` provider implements it (`'warmed'`) — the seam a
+   *   native metadata provider lights up so it is not duck-typed against the
+   *   JS manager's method. Otherwise falls back to full hydration on the
+   *   built-in JS manager — every persisted field's sparse index is loaded
+   *   from storage (`MetadataIndexManager.hydrateAll()`), not just the
+   *   heuristic common-fields subset `init()` warms — and reports `'warmed'`.
+   *   Neither seam present → `'unavailable'` (honest: `init()` is never used
+   *   as a substitute here, since a native provider's `init()` may be a
+   *   cheap verify rather than a real warm).
    * - **Graph**: calls the provider's own `warm?()` when the active graph
    *   provider implements it; otherwise re-runs its existing eager cold-load
    *   `init()` seam (idempotent — the JS adjacency index's `init()` already
@@ -14410,12 +14442,23 @@ export class Brainy<T = any> implements BrainyInterface<T> {
     // --- Metadata --------------------------------------------------------
     const metadataStart = Date.now()
     let metadataOutcome: WarmOutcome
+    const metadataProvider = this.metadataIndex as unknown as MetadataIndexProvider
     const metadataWithHydrate = this.metadataIndex as unknown as { hydrateAll?: () => Promise<void> }
-    if (typeof metadataWithHydrate.hydrateAll === 'function') {
+    if (typeof metadataProvider.warm === 'function') {
+      // Active provider (e.g. a native metadata index) declares its own warm
+      // seam — route through it FIRST so a native provider's warmth is
+      // reported honestly instead of being duck-typed against the JS
+      // manager's hydrateAll(), which a native provider does not implement.
+      await metadataProvider.warm()
+      metadataOutcome = 'warmed'
+    } else if (typeof metadataWithHydrate.hydrateAll === 'function') {
+      // Built-in JS manager path — full sparse-index hydration.
       await metadataWithHydrate.hydrateAll()
       metadataOutcome = 'warmed'
     } else {
-      // No hydration seam on this metadata provider — nothing to run.
+      // No hydration seam on this metadata provider — nothing to run. (No
+      // init() fallback here: init() on a native provider may be a cheap
+      // verify, and reporting that as warmth would lie.)
       metadataOutcome = 'unavailable'
     }
     const metadataDurationMs = Date.now() - metadataStart
@@ -14449,6 +14492,63 @@ export class Brainy<T = any> implements BrainyInterface<T> {
     }
   }
 
+  /**
+   * Read each index surface's self-reported outstanding maintenance work —
+   * the observability seam so an operator sees a grind coming (rising
+   * pending bytes/items, a stalled background pass) instead of discovering
+   * it as a CPU storm or a transaction blowing its budget mid-flight (see
+   * {@link TransactionTimeoutError}).
+   *
+   * PURE PASSTHROUGH: for each of vector/metadata/graph, this calls ONLY the
+   * ACTIVE provider's own `maintenanceDebt?()` hook (the same per-surface
+   * provider resolution {@link Brainy.warm} uses) and reports its
+   * {@link ProviderMaintenanceDebt} payload verbatim. There is no JS-side
+   * fallback computation, no threshold evaluation, and no polling — brainy
+   * surfaces the truth the provider measured; the provider owns the numbers
+   * and the operator owns the policy (what threshold matters, what action to
+   * take). A surface whose active provider does not implement the hook
+   * reports `'unavailable'` — never a guessed or zeroed payload.
+   *
+   * @returns A {@link MaintenanceDebtReport}: per-surface outcome + payload.
+   * @example
+   * ```typescript
+   * const debt = await brain.maintenanceDebt()
+   * if (debt.metadata.outcome === 'reported' && debt.metadata.debt?.pendingBytes) {
+   *   console.log('metadata pending bytes:', debt.metadata.debt.pendingBytes)
+   * }
+   * ```
+   */
+  async maintenanceDebt(): Promise<MaintenanceDebtReport> {
+    await this.ensureInitialized({ needs: ['vector', 'metadata', 'graph'] })
+
+    // --- Vector ---------------------------------------------------------
+    const vectorProvider = this.index as VectorIndexProvider & {
+      maintenanceDebt?: () => Promise<ProviderMaintenanceDebt>
+    }
+    const vector =
+      typeof vectorProvider.maintenanceDebt === 'function'
+        ? { outcome: 'reported' as const, debt: await vectorProvider.maintenanceDebt() }
+        : { outcome: 'unavailable' as const }
+
+    // --- Metadata --------------------------------------------------------
+    const metadataProvider = this.metadataIndex as unknown as MetadataIndexProvider
+    const metadata =
+      typeof metadataProvider.maintenanceDebt === 'function'
+        ? { outcome: 'reported' as const, debt: await metadataProvider.maintenanceDebt() }
+        : { outcome: 'unavailable' as const }
+
+    // --- Graph -------------------------------------------------------------
+    const graphProvider = this.graphIndex as GraphIndexProvider & {
+      maintenanceDebt?: () => Promise<ProviderMaintenanceDebt>
+    }
+    const graph =
+      typeof graphProvider.maintenanceDebt === 'function'
+        ? { outcome: 'reported' as const, debt: await graphProvider.maintenanceDebt() }
+        : { outcome: 'unavailable' as const }
+
+    return { vector, metadata, graph }
+  }
+
   /**
    * Explicitly warm up the embedding engine
    *