Refactor SettingsDefaultsManager: Move to shared directory and update imports

- Moved SettingsDefaultsManager from worker/settings to shared directory.
- Updated all import paths across the codebase to reflect the new location.
- Removed early-settings.ts as its functionality is now handled by SettingsDefaultsManager.
- Adjusted logger and paths to utilize SettingsDefaultsManager for configuration values.

CLAUDE.md

@@ -57,7 +57,13 @@ Settings are managed in `~/.claude-mem/settings.json`. The file is auto-created
 - `CLAUDE_MEM_PYTHON_VERSION` - Python version for uvx/chroma-mcp (default: 3.13, avoids onnxruntime compatibility issues with Python 3.14+)
 - `CLAUDE_CODE_PATH` - Path to Claude executable (default: auto-detect via 'which claude')
 
-**Note:** Environment variables can be used to temporarily override settings from the file.
+**Settings File Format:**
+```json
+{
+  "CLAUDE_MEM_MODEL": "claude-haiku-4-5",
+  "CLAUDE_MEM_WORKER_PORT": "37777"
+}
+```
 
 ## File Locations