Plexamp Lite 1.14.1: read-ahead no longer cut off ("Unexpected end of stream")

Two causes, both fixed:
- Plex keeps one file stream per device and cuts the one in progress when another starts, so the read-ahead
  and the player cut each other off. Whole-file fetches (read-ahead, downloads, download-first) now ask for
  the file as a download (?download=1), which Plex leaves out of that rule; the plain address follows for
  servers that refuse downloads.
- Http.abort closed the socket of a response already read to the end, whose connection was back in the pool
  and could be carrying the read-ahead. abort now leaves finished responses alone (test/PoolAbortTest.java).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

spec.md

@@ -48,6 +48,8 @@ over a Bluetooth speaker.
 - This repo's `tools/setup_toolchain.sh`, `make_roots.py` and `signapk.py` prepare the toolchain all the
   Galaxy Mini apps use: changes there affect every app.
 - Installs to internal storage (SD-card installs get killed during USB sharing).
+- Whole-file fetches of a part (read-ahead, downloads) use `Library.downloadUrls` (`?download=1` first): Plex
+  cuts a device's file stream when the same device starts another, except for downloads.
 - `platform/api8` and `platform/api16` keep the same `Platform` methods; shared code calls no API the API 8 jar
   lacks (the api8 compile and Dalvik check catch it). Each build's `versionCode` is the manifest's × 100 + level,
   same key; both APKs are listed in `../tenda-lite/repo/apps.json`.