fork: add README-translation.md explaining the fork

A short readme so anyone stumbling on this repo understands:
- what it is (Fossify Messages with on-the-fly translation via
  offline-translator AIDL)
- that it's an experiment, not a maintained project — no commitment
  to keep it up to date or ship fixes
- how to use it (install offline-translator first, opt in per source
  language)
- the dependency story (dev.davidv.translator, bundled ML Kit
  language identification, transitional)
- what's intentionally different from upstream Fossify (package id,
  no default-SMS prompt, sideload warning silenced)
- build instructions

Includes five screenshots in docs/:
- conversation-list.jpg — translated snippets in the main list
- thread-translated.jpg — Korean Amber Alert auto-translated to
  English, with the translate-icon toggle visible and numbers/URLs
  preserved verbatim
- thread-original.jpg — same thread flipped back to the original
- settings.jpg — Translation settings UI
- cab-translate.jpg — long-press Translate item

Fork-only — separate from the upstream-PR-candidate commits.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README-translation.md

@@ -0,0 +1,141 @@
+# SMS translation fork of Fossify Messages
+
+A small fork of [Fossify Messages](https://github.com/FossifyOrg/Messages) that
+auto-translates received SMS / MMS on-the-fly, on-device, with no cloud and
+no API keys.
+
+## Why this might be interesting
+
+If you live somewhere where you get important SMS in a language you don't
+read fluently (bank alerts, delivery notifications, OTPs, government
+messages…), this lets you keep using a clean FOSS messaging app and still
+understand them.
+
+The translation itself is sub-second per message, runs entirely on-device
+(Mozilla Bergamot / Marian NMT models), and preserves numbers and URLs
+verbatim — so OTP codes, account numbers, tracking links, etc. don't get
+mangled.
+
+- **Auto-translate**: each received bubble swaps to its translation as it
+  scrolls into view; conversation-list snippets do the same.
+- **Per-language opt-in**: you choose which source languages get auto-
+  translated (e.g. Korean → English) and which are left alone (e.g.
+  Swedish, German, anything else you already read).
+- **Tap to flip**: a small icon next to each translated bubble toggles it
+  back to the original.
+- **Manual translate**: long-press a bubble → ⋮ → **Translate** to force a
+  one-off translation even for languages not on your auto-translate list.
+- **Copy / Share / Select** capture what you see on screen — if the bubble
+  is showing English, your clipboard gets English.
+
+## Screenshots
+
+| Conversation list | Thread (translated) | Thread (original toggled back) |
+|---|---|---|
+| ![Conversation list with translated snippets](docs/conversation-list.jpg) | ![Korean SMS auto-translated to English, numbers and URLs preserved](docs/thread-translated.jpg) | ![Same thread flipped back to the Korean originals](docs/thread-original.jpg) |
+| Snippets are translated as you scroll, opted-in source languages only. | Auto-translate fires on view; the small icon below each bubble is the toggle. Numbers (145cm, 40kg, 112) and URLs (vo.la/1Pa9m) survive verbatim. | Tap the icon to flip a bubble back to its original. Tap again to flip back. |
+
+| Translation settings | Manual translate (CAB ⋮) |
+|---|---|
+| ![Translation settings screen — master toggle, target language, source allowlist](docs/settings.jpg) | ![Long-press menu on a bubble showing the Translate item](docs/cab-translate.jpg) |
+| Pick which source languages auto-translate and your target. Off by default. | Long-press → ⋮ → Translate to force a one-off translation for non-allowlisted languages. |
+
+## Status — please read
+
+This is an **experiment**, not a maintained project.
+
+- No commitment to keep it up to date with upstream Fossify or with Android.
+- No commitment to fix bugs or ship security updates.
+- No releases on F-Droid or Play. Built and signed locally by the author.
+- I'd like to propose the core feature upstream to Fossify Messages
+  eventually; if they accept it, this fork's reason to exist mostly goes
+  away. If they don't, I'll probably keep using my own build, but you
+  should not depend on it.
+
+If you want a clean, maintained build of Fossify Messages, install the
+official one from F-Droid. This fork is for tinkerers and for people who
+specifically want the translation behavior described above.
+
+## Dependencies
+
+1. **`dev.davidv.translator`** — the [offline-translator](https://github.com/DavidVentura/offline-translator)
+   app on F-Droid. This is the engine. Install it, open it, download the
+   language pack(s) for the languages you want to translate (e.g. Korean,
+   the source side, plus the target language pack if it asks). It runs
+   Mozilla's Bergamot translation models on-device.
+
+   Without this app installed, the translation feature silently does
+   nothing — the messaging app still works as a plain SMS client.
+
+2. **ML Kit Language Identification** — bundled inside this APK
+   (`com.google.mlkit:language-id`, Apache-2.0). Used only for detecting
+   what language an incoming SMS is in, so we can decide whether to
+   translate it. About 4 MB of model data baked in. This is transitional:
+   if davidv accepts a small AIDL addition upstream
+   ([offline-translator issue](https://github.com/DavidVentura/offline-translator))
+   we'll drop ML Kit and use his detection directly.
+
+3. **Android 8.0+** (same as upstream Fossify).
+
+## How to use
+
+1. Install **offline-translator** from F-Droid. Open it and download the
+   language packs for the source language(s) you want translated (e.g.
+   Korean) and confirm your target language pack is installed (usually
+   English).
+2. Install this fork's APK (build it yourself — see below).
+3. Open this app → top-right ⋮ → **Settings** → **Translation**:
+   - Turn on **Translate received messages**.
+   - Pick your **Translate into** target (defaults to your device language).
+   - Check the **Auto-translate from** languages you want auto-translated.
+4. Open any conversation. Bubbles in opted-in languages translate as you
+   scroll. Tap the small translate icon below a bubble to flip between
+   original and translation.
+
+## How it differs from upstream Fossify Messages
+
+The fork-only changes (not for upstream):
+
+- **Different package ID** (`net.jeena.smstranslate`) so it installs
+  alongside any official Fossify Messages.
+- **No "make me default SMS app" prompt** on first launch. You can still
+  make it the default via Android Settings → Default apps → SMS app if you
+  want — this just doesn't pester you about it.
+- **Sideload warning suppressed**. Fossify's built-in
+  "this APK looks corrupted, go get the official one" dialog is silenced
+  because of course this APK isn't the official one — it's a fork.
+
+The translation feature itself lives in a separate `:translate` Gradle
+module and is structured so it can be cherry-picked onto upstream cleanly
+as a possible PR.
+
+## Building from source
+
+You need JDK 17 and the Android SDK.
+
+```bash
+export JAVA_HOME=/path/to/jdk17
+export ANDROID_HOME=/path/to/android-sdk
+git clone <this repo>
+cd sms-translate
+./gradlew :app:assembleFossDebug
+# APK at app/build/outputs/apk/foss/debug/messages-*-foss-debug.apk
+adb install -r app/build/outputs/apk/foss/debug/messages-*-foss-debug.apk
+```
+
+If you want a release build, set up a `keystore.properties` per upstream
+Fossify's instructions and `./gradlew :app:assembleFossRelease`.
+
+## License
+
+Same as upstream Fossify Messages: **GPL-3.0**. The AIDL stubs from
+offline-translator are also GPL-3.0. ML Kit is Apache-2.0.
+
+## Credits
+
+- [Fossify Messages](https://github.com/FossifyOrg/Messages) — the
+  excellent FOSS messaging app this is a fork of.
+- [David Ventura](https://github.com/DavidVentura) — author of
+  [offline-translator](https://github.com/DavidVentura/offline-translator),
+  which does all the actual translation.
+- [Mozilla Bergamot](https://browser.mt/) — the underlying NMT models.