docs: document package model experience

packages/ui/app-boot/README.md

@@ -13,3 +13,9 @@ Shared boot glue for the app bins ([`dsh-stdio-agent`](../stdio-agent/README.md)
 Two failure classes the guards handle: `loader.await()` swallows init rejections (`Promise.allSettled`) — Node still exits non-zero on the resulting unhandled rejection, and `installFailLoud` replaces the noisy dump with one labelled line and a guaranteed `exit(1)`; a failed plugin IMPORT is only logged by the Loader (the process would otherwise exit 0 on a usable config typo), leaving a fiber-less entry that `assertEntriesLoaded` turns into a `boot()` rejection.
 
 Bare plugin specifiers in a config (`@deepseek-ai/dsh-*`) resolve through the cordis Loader's internal module loader, active only under `node --expose-internals`; the bins' subprocess smokes exercise that path, while this package's unit suite drives `boot()` in-process against configs with relative specifiers.
+
+## Model Experience
+
+| Context surface | What the model sees | Token effect |
+|---|---|---|
+| None directly | Boot and environment helpers load the configured plugin tree but register no prompt, schema, or message of their own. `.env`, loader diagnostics, and config-path selection are process concerns, not model context. | Zero direct tokens. The selected configuration indirectly determines which other packages contribute context. |