Bug: InMemory and SQLite backends require resource_id but create_memory_item() doesn't provide it

Summary

InMemoryMemoryItemRepository.create_item() and SQLiteMemoryItemRepository.create_item() require a mandatory resource_id parameter, but CRUDMixin._patch_create_memory_item() in crud.py doesn't provide it when calling create_item(). This causes a runtime error when trying to create memory items using InMemory or SQLite backends.

Version Information

• memU version: 1.4.0 (commit: 777f1ed)
• Python version: 3.13.12
• Database backends affected: InMemory, SQLite

Steps to Reproduce

from memu.app import MemoryService

memory_service = MemoryService(
    llm_profiles={"default": {...}},
    memorize_config={"memory_categories": [...]},
)

# This will fail with InMemory or SQLite backend
await memory_service.create_memory_item(
    memory_type="event",
    memory_content="Test message",
    memory_categories=["Conversations"],
)

Error Message

TypeError: InMemoryMemoryItemRepository.create_item() missing 1 required keyword-only argument: 'resource_id'

Root Cause

In src/memu/app/crud.py:512-517, the _patch_create_memory_item() method calls:

item = store.memory_item_repo.create_item(
    memory_type=memory_payload["type"],
    summary=memory_payload["content"],
    embedding=content_embedding,
    user_data=dict(user or {}),
)
# Missing resource_id parameter!

However, the method signatures differ across backends:

PostgreSQL (Fixed in PR #232)

def create_item(
    self,
    *,
    resource_id: str | None = None,  # ✓ Optional
    ...
)

InMemory & SQLite (Still broken)

def create_item(
    self,
    *,
    resource_id: str,  # ✗ Required
    ...
)

Expected Behavior

All database backends should have consistent signatures. Since create_memory_item() API doesn't expose resource_id to users, the backends should make it optional (like PostgreSQL was fixed in #232).

Actual Behavior

InMemory and SQLite backends throw a TypeError because resource_id is required but not provided.

Possible Solutions

1. Make resource_id optional in InMemory and SQLite backends (recommended)

   • Change resource_id: str to resource_id: str | None = None
   • Consistent with PostgreSQL backend
   • Maintains backward compatibility

2. Pass a default resource_id in crud.py

   • Less ideal as it doesn't address the inconsistency

Related Issues/PRs

• PR fix: allow nullable resource_id in Postgres items #232: Fixed this for PostgreSQL backend only
• This issue extends the fix to InMemory and SQLite backends

Additional Context

This affects all users who want to use InMemory or SQLite backends with the create_memory_item() API, which is the standard flow for creating memories through the MemoryService interface.