docs: replace stale 'android' name mentions with 'iris'

The plugin is named 'iris' (IrisAdapter, IRIS_HOME_CHANNEL, label Iris),
but several docs still referred to it as the android platform/plugin and
to the product as 'the Android app'. Rename name-mentions to iris/IRIS
and product-mentions to 'Iris app'; keep legitimate OS references
(androidApp, Android SDK, Android 10, androidx, test_android.py, ...).

Also includes pi-lens markdown-lint autofixes (table spacing, trailing
newlines) in the touched files.

docs/00-overview.md

@@ -11,8 +11,8 @@ create.
 
 ## Goals
 
-- **Native feel.** Real Android app (Kotlin/Compose), not a WebView. Desktop
-  app that is the same app, resized for a big screen.
+- **Native feel.** Real native app (Iris on Android, Kotlin/Compose), not a
+  WebView. Desktop app that is the same app, resized for a big screen.
 - **First-class gateway citizen.** The app is a hermes *messaging platform*, so
   everything the gateway already does "just works": slash commands, cron
   delivery, `send_message` routing, coexistence with Telegram/Discord/etc.