chore(android): publish companion as raw APK instead of zip

Serve the companion download as a plain .apk so a phone installs it
straight from the link/QR with no unzip step. Repoint the in-app
download URL, the ship + publish scripts, and the pre-push hook at
archipelago-companion.apk, and drop the legacy .apk.zip.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.githooks/pre-push

@@ -2,7 +2,7 @@
 # Keep the served companion APK in sync with main on every push.
 #
 # When a push to main includes Android changes, rebuild the APK, refresh
-# neode-ui/public/packages/archipelago-companion.apk.zip, commit it, and ask
+# neode-ui/public/packages/archipelago-companion.apk, commit it, and ask
 # you to push again (so the refreshed APK rides along in the same push).
 #
 # Enable once per clone:  git config core.hooksPath .githooks
@@ -40,7 +40,7 @@ fi
 
 bash scripts/publish-companion-apk.sh || exit 0
 
-DEST="neode-ui/public/packages/archipelago-companion.apk.zip"
+DEST="neode-ui/public/packages/archipelago-companion.apk"
 if git diff --cached --quiet -- "$DEST"; then
   exit 0   # APK unchanged — nothing to do
 fi