List User Schemas V1

List all schemas accessible to the authenticated user.

Returns schemas that the user owns or has read access to, including:
- Personal schemas created by the user
- Workspace schemas shared within the user's workspace (legacy)
- Namespace schemas shared within the user's namespace
- Organization schemas available to the user's organization

**Authentication Required**:
One of the following authentication methods must be used:
- Bearer token in `Authorization` header
- API Key in `X-API-Key` header
- Session token in `X-Session-Token` header