fable-anthropic/claude-fable-5 — reverse-engineered prompt

Build me a native desktop app for Windows and macOS that feels like a serious local client for Claude Fable 5. I want to sign in with my Claude account, start long running chats, and keep all my project history, prompts, and workspaces stored on my own machine with no telemetry. The app should let me drag in logs, config files, docs, and code folders so it can help with big coding jobs, security reviews, and deep analysis without feeling stuck in a browser tab.

Please include a clean desktop UI with a project vault, searchable session history, and a way to index a whole codebase so the assistant can understand and work across multiple files. Add a security scanner style flow for reviewing system logs and configs, and make sure API traffic goes straight to Anthropic rather than any middle layer. Privacy should be a big deal here, including local storage and encrypted history if possible. If anything is unclear, look up current Anthropic desktop and API docs online and make it polished enough to ship.