Show crests and league sections when picking a club

The club chooser was a flat list of 56 names in a generic picker
dialog, which is unreadable from a couch. It now has its own dialog
with a crest per row, the short label on the right, and section
headers per division. Enabled clubs in the settings card show their
crest too.

A search field would have been the obvious alternative, but text
entry on a remote is exactly what the Ten-Foot rule rules out, so
grouping plus crests carries the recognition instead.

Also adds tests/demo, a generator for neutral playlist and EPG data
so screenshots never carry real channel names.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/build.gradle.kts

@@ -12,8 +12,8 @@ android {
         applicationId = "dev.castarr.tv"
         minSdk = 26
         targetSdk = 35
-        versionCode = 36
-        versionName = "0.11.3"
+        versionCode = 37
+        versionName = "0.11.4"
     }
 
     // Release signing from environment (see ~/.keys/castarr-release.env on the