Memby v0.1.53: Android TV client plus gateway

Android TV client for Emby (Kotlin, Compose for TV) and the Memby gateway
(Go, Postgres, Redis) that fronts it.

Client:
- Setup, profiles, home rows, Media3 playback, system screensaver (Dream)
- Backend chosen at build time: gateway when memby.gatewayUrl is set,
  otherwise direct to Emby. Both paths stay working.
- Server-composed home rows, rendered verbatim so new row types ship
  without an app release
- Full-screen animated maintenance state, row engagement telemetry

Gateway:
- One request per TV screen; auth, caching, search and row shaping
- Library import from Emby into Postgres (manual, then hourly incremental)
- Recommendations from viewing history (recency-weighted genre affinity)
- Admin page for imports, an offline switch, and per-row analytics
- Video always direct-plays from Emby; only metadata passes through

Identity is com.ponzischeme89.memby throughout, replacing
com.mattcohen.embyclientsname. A changed applicationId installs as a new
app: TVs need a fresh sign-in and the old package uninstalled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/src/main/res/xml/emby_dream.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Screensaver metadata. "Customize" in the TV's screensaver settings opens the
+     app's MainActivity, where the server connection is configured. -->
+<dream xmlns:android="http://schemas.android.com/apk/res/android"
+    android:settingsActivity="com.ponzischeme89.memby/.ui.MainActivity"
+    android:previewImage="@drawable/app_banner" />