Memphis-Chains

Drive a Memphis hotfix end-to-end with the cross-layer grid as a forcing function. Use when fixing a bug that may touch more than one layer (Rust core, NAPI bridge, TS host, CLI, Tauri, doctor/status, tests). Auto-loads the grid template, the bundled-PR Codex pattern, and the rebuild reminder.

Rebuild Memphis NAPI binary after Rust crate changes and verify the runtime will see the new code. Use whenever crates/memphis-{core,operator,napi,vault,tui,case-index,embed}/ source has been modified.