feat: COW always-on architecture + cloud storage clear() fix (v5.11.0)

Major architectural improvements and critical bug fixes:

## COW Always-On Architecture
- Removed cowEnabled flag from BaseStorage (COW cannot be disabled)
- Eliminated marker file system (checkClearMarker, createClearMarker)
- Simplified all code paths to assume COW is always enabled
- COW automatically re-initializes after clear() operations

## Critical Bug Fix: Cloud Storage clear()
- Fixed GCS clear() using correct paths (branches/ instead of entities/nouns/)
- Fixed S3Compatible clear() path structure
- Fixed R2 clear() implementation
- Fixed Azure, FileSystem, OPFS, Memory clear() COW flag handling
- clear() now deletes: branches/, _cow/, _system/
- Result: Cloud buckets can now be fully cleared (previously impossible)

## Container Memory Detection
- Auto-detect Docker/K8s/Cloud Run memory limits (cgroup v1/v2)
- Smart memory allocation (75% graph data, 25% query operations)
- Environment variable support (CLOUD_RUN_MEMORY, MEMORY_LIMIT)
- Production-grade containerized deployment support

## CommitLog streamHistory Feature
- Added streamable commit history with pagination
- Efficient memory usage for large commit histories
- Support for branch filtering and time ranges

## Comprehensive Storage Documentation
- Complete v5.11.0 file structure reference
- Detailed path construction algorithms
- 8 common storage scenarios with examples
- Type-first storage, sharding, COW architecture explained
- Public docs: docs/architecture/data-storage-architecture.md (1063 lines)

## Files Modified (14 files)
- All 8 storage adapters (GCS, S3, R2, Azure, FS, OPFS, Memory, Historical)
- BaseStorage core architecture
- CommitLog with streaming
- Brainy memory configuration
- Parameter validation with container detection
- Storage architecture documentation

## Breaking Changes
NONE - COW was already enabled by default. This removes the ability to disable it.

## Migration
No action required. Upgrade and clear() will work correctly on cloud storage.

## Impact
- Users can now clear cloud storage buckets completely
- No more corrupted buckets after clear() operations
- Container deployments automatically optimize memory allocation
- COW is mandatory and always enabled (safer, simpler)

v5.11.0 - Production ready

src/storage/adapters/memoryStorage.ts

@@ -202,19 +202,10 @@ export class MemoryStorage extends BaseStorage {
    * @returns Always false (marker doesn't persist in memory)
    * @protected
    */
-  protected async checkClearMarker(): Promise<boolean> {
-    return false // MemoryStorage doesn't persist - marker doesn't survive restart
-  }
-
   /**
-   * Create marker indicating COW has been explicitly disabled
-   * v5.10.4: No-op for MemoryStorage (doesn't persist)
-   * @protected
+   * v5.11.0: Removed checkClearMarker() and createClearMarker() methods
+   * COW is now always enabled - marker files are no longer used
    */
-  protected async createClearMarker(): Promise<void> {
-    // No-op: MemoryStorage doesn't persist, so marker is not needed
-    // clear() in memory already resets all state, no marker survives restart
-  }
 
   /**
    * Save statistics data to storage