council_read was a sandboxed readFile wrapper for .sisyphus/ archives.
Now that council_finalize extracts member responses into plain files,
the standard Read tool serves the same purpose. Removes the tool, its
tests, and updates Athena's prompt to reference Read directly.
- council_finalize: batch extract, archive, and return council results
- council_read: secure file reader for archived council responses
- background_wait: stripped to metadata-only, returns completed_tasks array
- Removed all council-specific logic from background_wait
- 28/28 tests passing across all changed files