Main-screen recordings list, player actions, background recording, exports (1.4.0-alpha)

- Main screen: recordings list at the bottom (newest first); removed the separate
  library screen and the top-right link
- Player: delete/rename/share/export, no autoplay, embedded-marker fallback
- Word-level tap-to-seek from Whisper token timestamps (length fallback)
- Export transcripts as .txt + .srt to Downloads
- RecordingService: microphone foreground service for background recording
- FileProvider for sharing on Android 9 and older
- StreamingResampler extracted to its own class + JUnit regression tests
- Bump to 1.4.0-alpha (versionCode 6)

1 files changed, 28 insertions, 25 deletions

diff --git a/README.md b/README.md
index 0cf9692..8785d1c 100644
--- a/README.md
+++ b/README.md
@@ -9,15 +9,12 @@ on device.
 - **Mono switch:** optionally record a single channel (half the file size)
 - **Markers:** place labelled cue points while recording; they are embedded in the WAV (`cue ` + `LIST/adtl`) and shown in the player
 - **Silence:** optional Do Not Disturb total silence (no notifications, no vibration) while recording
-- **Saving:** the WAV is written to the public **Downloads** folder as
-  `reccoon-YYYY-MM-DD-HHMMSS-XXXXX.wav`, where `XXXXX` is a persistent
-  5-digit progressive counter
-- **Library:** a list of saved recordings, with a player and a scrubber to jump
-  around long recordings
+- **Recordings list:** scrollable list at the bottom of the main screen, newest first
+- **Player:** scrubber, ±10 s jumps, speed control, delete / rename / share / export, no autoplay
 - **Transcription:** on-device, offline speech recognition with
   [sherpa-onnx](https://github.com/k2-fsa/sherpa-onnx) using multilingual
   Whisper — works with **English and Italian**
-- **Name:** RECCoon · **by** wuhei · **version** 1.3.1-alpha
+- **Name:** RECCoon · **by** wuhei · **version** 1.4.0-alpha
 - **Icon:** raccoon with a microphone
 
 ## Requirements
@@ -32,6 +29,7 @@ on device.
 ```sh
 ./gradlew :app:assembleDebug      # debug APK
 ./gradlew :app:assembleRelease    # release APK (signed with the debug key)
+./gradlew :app:testDebugUnitTest  # JVM unit tests
 ```
 
 Outputs:
@@ -39,7 +37,7 @@ Outputs:
 - `app/build/outputs/apk/debug/app-debug.apk`
 - `app/build/outputs/apk/release/app-release.apk`
 
-A prebuilt copy is available at `dist/RECCoon-1.3.1-alpha.apk`. Note that the
+A prebuilt copy is available at `dist/RECCoon-1.4.0-alpha.apk`. Note that the
 sherpa-onnx AAR in `app/libs/` and the APK in `dist/` are **not** tracked in
 git because they are large; see `TODO.md`.
 
@@ -49,10 +47,14 @@ git because they are large; see `TODO.md`.
   44100 Hz into a temporary file, then rewrites a correct 44-byte RIFF/WAVE
   header when recording stops. It uses stereo when available and falls back to
   mono, and reports per-channel peak levels to the UI.
-- `MainActivity` handles the runtime permissions, the timer, and copying the
-  finished file into Downloads. On Android 10+ this uses `MediaStore`; on
-  older versions it writes directly to the public Downloads directory and
-  notifies the media scanner.
+- `RecordingService` is a microphone-typed foreground service started while
+  recording, so capture continues when the app is in the background.
+- `MainActivity` handles the runtime permissions, the timer, the level meters
+  and copying the finished file into Downloads. On Android 10+ this uses
+  `MediaStore`; on older versions it writes directly to the public Downloads
+  directory and notifies the media scanner.
+- Files are named `reccoon-YYYY-MM-DD-HHMMSS-XXXXX.wav`, where `XXXXX` is a
+  persistent 5-digit progressive counter.
 
 ## Waveform, meters and markers
 
@@ -63,20 +65,22 @@ git because they are large; see `TODO.md`.
 - The **Mark** button (enabled while recording) adds a labelled cue point at the
   current position. Markers are written into the WAV as standard `cue ` and
   `LIST/adtl` chunks (readable by Audacity/Reaper) by `WavRecorder`, and also
-  stored as a JSON sidecar by `MarkerStore`. `PlayerActivity` shows them as
-  chips that seek the player when tapped.
-- The **Mono** checkbox records a single channel instead of stereo.
-- The **Silence alerts** checkbox switches the phone to Do Not Disturb total
-  silence while recording and restores the previous setting on stop. It needs
-  the `ACCESS_NOTIFICATION_POLICY` permission, granted in system settings when
-  first enabled.
+  stored as a JSON sidecar by `MarkerStore`. The player reads the sidecar and
+  falls back to `WavMarkers`, which parses the embedded chunks.
 
-## Library and player
+## Recordings list and player
 
-- `RecordingsActivity` lists the `reccoon-*.wav` files in Downloads.
+- The main screen shows a scrollable list of recordings, newest first. Tapping a
+  row opens `PlayerActivity`.
 - `PlayerActivity` plays a file with the platform `MediaPlayer`, a scrubber
-  (`SeekBar`), ±10 s jumps and a playback speed control (0.5×–2×). Tapping a
-  transcript line seeks the player to that moment.
+  (`SeekBar`), ±10 s jumps and a playback speed control (0.5×–2×). Playback does
+  **not** start automatically.
+- Library actions: **Share** (FileProvider on Android 9 and older), **Rename**
+  (MediaStore or file), **Export** (writes `.txt` and `.srt` to Downloads) and
+  **Delete** (removes the WAV and its sidecars).
+- Transcript words are clickable: tapping a word seeks the player to it. Word
+  timings come from Whisper token timestamps when available, otherwise the
+  segment is divided between its words.
 
 ## On-device transcription
 
@@ -97,11 +101,10 @@ git because they are large; see `TODO.md`.
 - Language can be forced to English (`en`) or Italian (`it`), or left on
   **Auto detect**.
 - Transcripts are stored as JSON sidecars in app-private storage
-  (`filesDir/transcripts/<recording>.json`) and are shown in the player. A
-  `TXT` badge marks recordings that already have a transcript.
+  (`filesDir/transcripts/<recording>.json`).
 
 ## Native libraries and APK size
 
 The APK bundles the sherpa-onnx/onnxruntime native libraries for `arm64-v8a`
-and `x86_64`, so it is around 70 MB. Removing `x86_64` from the `abiFilters`
+and `x86_64`, so it is around 72 MB. Removing `x86_64` from the `abiFilters`
 in `app/build.gradle.kts` roughly halves the APK size for phone-only builds.