refactor(memory): isolate store write path from facade

[HugoSkylight]

Summary

• add explicit MemoryWriteDependencies assembled by CortexMemoryServices for the store write boundary
• move store helper services off CortexMemory/MemoryService wrapper callbacks and onto MemoryWriteService dependencies
• keep CortexMemory/MemoryService public compatibility wrappers and new bypass property access intact

Validation

• uv run --group dev pytest tests/test_memory_store_record_service.py tests/test_memory_write_context_builder.py tests/test_memory_write_derive_service.py tests/test_memory_write_embed_service.py tests/test_memory_write_dedup_service.py tests/test_memory_directory_record_service.py tests/test_write_dedup.py tests/test_http_server.py tests/test_memory_document_write_service.py -q
• uv run --group dev pytest tests/test_orchestrator_services.py tests/test_memory_service.py tests/test_knowledge_service.py tests/test_subsystem_bootstrapper.py tests/test_orchestrator_close.py -q
• uv run --group dev pytest tests/test_memory_write_dedup_service.py tests/test_write_dedup.py -q
• uv run --group dev ruff check src/opencortex/services/cortex_memory_services.py src/opencortex/services/memory_write_service.py src/opencortex/services/memory_service.py src/opencortex/services/memory_write_context_builder.py src/opencortex/services/memory_write_derive_service.py src/opencortex/services/memory_write_embed_service.py src/opencortex/services/memory_write_dedup_service.py src/opencortex/services/memory_directory_record_service.py src/opencortex/services/memory_store_record_service.py tests/test_memory_store_record_service.py tests/test_memory_write_context_builder.py tests/test_memory_write_dedup_service.py tests/test_memory_directory_record_service.py tests/test_orchestrator_services.py tests/test_memory_service.py
• uv run --group dev ruff format --check src/opencortex/services/cortex_memory_services.py src/opencortex/services/memory_write_service.py src/opencortex/services/memory_service.py src/opencortex/services/memory_write_context_builder.py src/opencortex/services/memory_write_derive_service.py src/opencortex/services/memory_write_embed_service.py src/opencortex/services/memory_write_dedup_service.py src/opencortex/services/memory_directory_record_service.py src/opencortex/services/memory_store_record_service.py tests/test_memory_store_record_service.py tests/test_memory_write_context_builder.py tests/test_memory_write_dedup_service.py tests/test_memory_directory_record_service.py tests/test_orchestrator_services.py tests/test_memory_service.py

Browser

• Not run: backend-only Python service/test diff with no browser route mapping.