Move Iris to its standalone repository

docs/PLAN.md

@@ -39,6 +39,13 @@ backend (Rust/Axum, desktop)
    └─ config.ron + per-session transcript files
 ```
 
+**Iris is developed in its own repository and pinned here as a submodule**
+(2026-09-12). The framework accumulated enough generally useful Android,
+desktop, layout, text, input, accessibility, rendering, and packaging work to
+stand independently of this product. Keeping it under `iris/` preserves the
+app's local path dependency and test commands, while the repository boundary
+keeps product code and framework code from sharing commits.
+
 ## Architecture
 
 ### Setups and providers (2026-08-28)