98f4c1aa9f
Update the project plan documentation to reflect recent architectural changes and planned features. This includes clarifying the role of Axum, the filesystem structure, endpoint definitions, and the management of prompts. Key changes: - Clarified Axum's role as a coordinator handling sequential workers and the web interface. - Adjusted filesystem structure to use user slugs instead of open/done directories and introduced a soft-delete marker. - Updated endpoint definitions to reflect current and planned API structures. - Removed the mention of `prompts.toml` as prompts are now hardcoded, with plans for future override capabilities. - Added detail on marker semantics for file states. - Refined the description of LLM provider configuration and its impact on the UI. - Introduced user-specific Whisper settings in `users.toml`.