fix: Use platform-native path separators in config.json

[groksrc]

Problem

Fixes #428

On Windows, the config.json file stores project paths using forward slashes (/) instead of platform-native backslashes (\). This causes issues when paths are used by Windows tools that expect backslash separators.

Example issue on Windows:

{
  "projects": {
    "main": "C:/Users/username/basic-memory"  // ❌ Wrong on Windows
  }
}

Expected on Windows:

{
  "projects": {
    "main": "C:\\Users\\username\\basic-memory"  // ✅ Correct
  }
}

Root Cause

The code used .as_posix() in three locations, which forces POSIX-style (Unix) forward slash separators regardless of platform:

• Line 66: Default project initialization
• Line 201: model_post_init method
• Line 364: add_project method

# ❌ Before: Forced forward slashes
config.projects[name] = project_path.as_posix()

# ✅ After: Uses platform-native separators
config.projects[name] = str(project_path)

Solution

Replaced .as_posix() with str() to preserve platform-native path separators:

• Windows: Uses backslashes (\)
• Unix: Uses forward slashes (/)

Changes

1. src/basic_memory/config.py

   • Fixed 3 locations using .as_posix()
   • Changed to use str(path) for platform-native separators

2. tests/test_config.py

   • Added 3 new tests for platform-specific path handling
   • Tests verify correct separator usage on both Windows and Unix
   • All 27 tests pass (24 existing + 3 new)

Testing

uv run pytest tests/test_config.py -v
# 27 passed in 1.54s

Test Coverage:

• test_project_paths_use_platform_native_separators_in_config - Verifies saved config uses correct separators
• test_add_project_uses_platform_native_separators - Tests ConfigManager.add_project()
• test_model_post_init_uses_platform_native_separators - Tests default project creation

Impact

This fix ensures:

• ✅ Windows users get properly formatted paths in config.json
• ✅ Unix systems continue to work as before
• ✅ Paths work correctly with platform-native tools
• ✅ No breaking changes for existing functionality

Related

• Issue Windows: config.json writes paths with forward slashes instead of backslashes #428: Windows config.json path separator issue

[jope-bm]

is this still using a forward slash between Path.home() and "basic-memory"?

[groksrc]

When you use / between Path objects (or between a Path and a string), it creates a new path by joining them together. So Path.home() / "basic-memory" is equivalent to joining the user's home directory with the "basic-memory" subdirectory.

This is syntactic sugar that pathlib provides to make path construction more readable. It's roughly equivalent to:
pythonPath.home().joinpath("basic-memory")