refactor(8.0)!: remove orphaned zero-config subsystem + dead cloud/progressive-init storage vestige

The old config-generation subsystem (src/config/ + autoConfiguration.ts) was
superseded during the 8.0 rework and never wired into init(): it emitted settings
for a partitioning subsystem that no longer exists and probed deleted cloud env
vars. The live zero-config path is inline — recall preset → HNSW knobs, storage
auto-detect, auto persistMode, container-memory-aware cache sizing.

The storage progressive-init / cloud-detection cluster was equally dead after the
cloud adapters were dropped: isCloudStorage() is permanently false (no overriders),
scheduleBackgroundInit/runBackgroundInit were never called (the latter an empty
body), initMode was never assigned, and Brainy.isFullyInitialized()/
awaitBackgroundInit() were always-trivial with zero callers. scheduleCountPersist()
collapses to its only-ever-taken immediate write-through path.

Removed:
- src/config/{index,zeroConfig,storageAutoConfig,modelAutoConfig,sharedConfigManager}.ts
- src/utils/autoConfiguration.ts + the inert BrainyZeroConfig export
- Brainy.isFullyInitialized()/awaitBackgroundInit() (+ BrainyInterface decls)
- InitMode type, isCloudStorage/detectCloudEnvironment/resolveInitMode,
  scheduleBackgroundInit/runBackgroundInit/ensureValidatedForWrite and their state
- Dead cloud env-var probes (K_SERVICE/K_REVISION/AWS_LAMBDA_FUNCTION_NAME/
  FUNCTIONS_TARGET/AZURE_FUNCTIONS_ENVIRONMENT)

Kept (verified live): production-detection logging (environment.ts), container-
memory cache sizing (memoryDetection/paramValidation), on-disk hash bucketing
(sharding.ts).

Docs: scrubbed deleted-subsystem references (JS quantization knobs, cloud/OPFS
adapters, partitioning, old zero-config API) across 14 files; deleted two wholly-
obsolete feature docs (complete-feature-list, v3-features); rewrote
architecture/zero-config for 8.0.

~3,700 LOC removed. Build clean; 1392 unit + 24 db-mvcc green.

docs/PERFORMANCE.md

@@ -391,13 +391,12 @@ await brain.init()  // Instant (0-10ms)
 
 ### Vector Index Tuning Knobs
 
-Brainy 8.0 exposes exactly three knobs on `config.vector`:
+Brainy 8.0 exposes two knobs on `config.vector`:
 
 ```javascript
 const brain = new Brainy({
   vector: {
     recall: 'fast',                // 'fast' | 'balanced' | 'accurate'
-    quantization: { bits: 8 },     // 4 | 8 (SQ4 / SQ8)
     persistMode: 'deferred'        // 'immediate' | 'deferred'
   }
 })