refactor(8.0): drop strictConfig — surface too small to justify the option (scaffold step 9)

Per user direction: after the step-8 simplification reduced
`config.vector` to three knobs (`recall`, `quantization`, `persistMode`),
the `strictConfig` field's only remaining job was warning about
`quantization.bits` being silently ignored on the cortex DiskANN path —
one mismatch case across the entire public surface.

That's not enough surface to justify a declared-but-undelivered config
field. Cleaner to drop it now; if 8.x or 9.0 adds enough provider-knob
mismatch cases to warrant a general-purpose strictness flag, we can add
it back then.

CHANGES

src/types/brainy.types.ts
- Removed BrainyConfig.strictConfig field + its JSDoc block.
- Removed the `strictConfig: 'warn' flags this at init time` reference
  from quantization JSDoc; replaced with a plain "silently ignored on
  DiskANN" note (cortex's B.4 contract still applies).

src/brainy.ts
- normalizeConfig() no longer emits a strictConfig field.

NO-OP scope

Field was declared but had no enforcement logic. Removing it is a pure
type-surface change. No behaviour change.

VERIFICATION

- npx tsc --noEmit: clean
- npm test: 1408 / 1409 (same pre-existing race-condition outstanding)

src/brainy.ts

@@ -9289,9 +9289,6 @@ export class Brainy<T = any> implements BrainyInterface<T> {
       // { except: [...] }: strict, but listed types may omit subtype.
       // Becomes the default in 8.0.0.
       requireSubtype: config?.requireSubtype ?? false,
-      // Provider-knob mismatch strictness (8.0). Default is 'warn' (one-shot
-      // teaching message). See BRAINY-8.0-RENAME-COORDINATION § B.6.
-      strictConfig: config?.strictConfig ?? 'warn',
       // Multi-process safety
       mode: config?.mode ?? 'writer',
       force: config?.force ?? false

src/types/brainy.types.ts

@@ -1145,7 +1145,7 @@ export interface BrainyConfig {
      * `distance:sq4` SIMD providers accelerate them when available.
      *
      * Silently ignored on a native DiskANN-style provider path (it uses its
-     * own PQ math); `strictConfig: 'warn'` flags this at init time.
+     * own PQ math instead).
      */
     quantization?: {
       enabled?: boolean
@@ -1220,30 +1220,6 @@ export interface BrainyConfig {
    */
   requireSubtype?: boolean | { except: Array<import('../types/graphTypes.js').NounType | import('../types/graphTypes.js').VerbType> }
 
-  /**
-   * Validation strictness for provider-knob mismatches (Brainy 8.0).
-   *
-   * When a registered provider silently ignores a configuration knob the
-   * user passed (e.g. `config.vector.advanced.diskann.*` on the open-core JS
-   * HNSW path, or `config.vector.advanced.hnsw.*` on a native DiskANN-style
-   * path), the user otherwise gets no feedback that their override has no
-   * effect. This option controls the response:
-   *
-   * - `false` — no enforcement. Mismatched knobs are silently accepted.
-   * - `'warn'` — (default in 8.0) one-shot warning per call site via
-   *   `prodLog.warn`, listing the ignored knobs and the docs link to the
-   *   appropriate `advanced.*` escape hatch.
-   * - `true` — hard error at `init()`. Refuses to start until the config
-   *   is consistent with the resolved provider impl.
-   *
-   * The warning / error format matches the 7.30.1 teaching-error pattern:
-   * problem → escape valves → caller location → docs link.
-   *
-   * **Contract** locked in handoff thread BRAINY-8.0-RENAME-COORDINATION
-   * § B.6 (cortex-confirmed 2026-06-09).
-   */
-  strictConfig?: boolean | 'warn'
-
   /**
    * Process role for multi-process safety on filesystem storage.
    *