Summary

Document the custom memory pool and pool allocator implementations used internally by container_system for high-performance memory allocation.

Parent Issue

Part of: [EPIC] docs: Address documentation gaps across all ecosystem systems (kcenon/common_system#325)

Background (Why)

container_system uses custom memory management to achieve its benchmark performance (5M containers/sec creation, 25M ops/sec). The memory pool and allocator are key to this performance but completely undocumented.

Source files:

• internal/memory_pool.h — Fixed-size memory pool implementation
• internal/pool_allocator.h — STL-compatible allocator using the memory pool

Scope (What)

Create docs/advanced/MEMORY_MANAGEMENT.md covering:

1. Memory Pool (memory_pool.h)

• Pool architecture (fixed-size block allocation)
• Block sizing strategy
• Free list management
• Growth/expansion policy
• Thread safety model

2. Pool Allocator (pool_allocator.h)

• STL allocator interface compliance
• Integration with standard containers
• Rebind support
• Stateful vs stateless allocator design

3. Internal Usage

• Which container types use pool allocation
• Allocation patterns during container operations
• Memory layout of pooled containers

4. Performance Analysis

• Allocation/deallocation throughput vs malloc/new
• Memory fragmentation characteristics
• Cache locality benefits
• Benchmark comparison data

5. Configuration

• Pool size configuration
• Pre-allocation strategies
• Memory limit enforcement

6. Best Practices

• When pool allocation helps vs standard allocation
• Sizing recommendations for different workloads
• Memory monitoring and leak detection

Acceptance Criteria

• Memory pool architecture documented with diagram
• Pool allocator STL interface documented
• Internal usage patterns explained
• Performance comparison with standard allocators
• Configuration options documented
• Best practices provided