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superseded during the 8.0 rework and never wired into init(): it emitted settings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/guides/quick-start.md

@@ -108,4 +108,4 @@ await brain.find({ query: 'people who work at Anthropic' })
 - [Triple Intelligence](/docs/concepts/triple-intelligence) — understand how the query engine works
 - [The Find System](/docs/guides/find-system) — advanced queries, operators, and graph traversal
 - [API Reference](/docs/api/reference) — complete method documentation
-- [Storage Adapters](/docs/guides/storage-adapters) — S3, GCS, Azure, filesystem, OPFS
+- [Storage Adapters](/docs/guides/storage-adapters) — filesystem, memory