Wire memopop-native to the FastAPI sidecar

End-to-end plan for closing the loop from Tauri click to live log stream — Rust dispatcher forwards JSON, browser EventSource handles SSE, sidecar spawns lazily.

• Tauri-Framework
• FastAPI
• Sidecar-Process
• Rust
• SSE
• Server-Sent-Events
• Integration
• Memopop-Native