fix: prevent circuit breaker activation and data loss during bulk imports

Storage-aware batching system prevents rate limiting issues on cloud storage (GCS, S3, R2, Azure). Replaces entity-by-entity creation with addMany()/relateMany() batch operations in ImportCoordinator. Separate read/write circuit breakers prevent read lockouts during write throttling. Each storage adapter auto-configures optimal batch sizes and delays. Fixes silent data loss and 30+ second lockouts on 1000+ row imports.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/storage/adapters/fileSystemStorage.ts

@@ -16,6 +16,7 @@ import {
 } from '../../coreTypes.js'
 import {
   BaseStorage,
+  StorageBatchConfig,
   SYSTEM_DIR,
   STATISTICS_KEY
 } from '../baseStorage.js'
@@ -119,6 +120,31 @@ export class FileSystemStorage extends BaseStorage {
     // Defer path operations until init() when path module is guaranteed to be loaded
   }
 
+  /**
+   * Get FileSystem-optimized batch configuration
+   *
+   * File system storage is I/O bound but not rate limited:
+   * - Large batch sizes (500 items)
+   * - No delays needed (0ms)
+   * - Moderate concurrency (100 operations) - limited by I/O threads
+   * - Parallel processing supported
+   *
+   * @returns FileSystem-optimized batch configuration
+   * @since v4.11.0
+   */
+  public getBatchConfig(): StorageBatchConfig {
+    return {
+      maxBatchSize: 500,
+      batchDelayMs: 0,
+      maxConcurrent: 100,
+      supportsParallelWrites: true,  // Filesystem handles parallel I/O
+      rateLimit: {
+        operationsPerSecond: 5000,  // Depends on disk speed
+        burstCapacity: 2000
+      }
+    }
+  }
+
   /**
    * Initialize the storage adapter
    */