feat(watch): vertical PoC — record, upload, playback end-to-end

Completes the 5-second-record-and-upload flow:
- RecordingViewModel orchestrates recorder, countdown, and upload
- MediaRecorder wrapper produces 16kHz/AAC-LC m4a (Whisper-compatible)
- Compose RecordingScreen renders the state pyramid
  (Idle / RequestingPermission / Recording / Uploading / Success / Error)
- UiState + pure reducer with full JVM unit-test coverage
- run.sh "test" subcommand wraps the unit and instrumented tiers
  (set SKIP_INSTRUMENTED=1 to bypass the on-device tier)

Verified end-to-end: emulator captures "Hallo, hallo", lands at
tmpdata/<user>/<case>/*.m4a, Whisper transcribes, Ollama classifies,
document.md is written — full pipeline in ~5s.

Known: MockWebServer-based UploadClientTest hangs in setUp on the
Wear OS 34 emulator (likely SELinux socket policy). Deferred — the
real-server end-to-end already validates the wire protocol.

watch/wearos/app/src/androidTest/java/com/doctate/watch/net/UploadClientTest.kt

@@ -81,9 +81,12 @@ class UploadClientTest {
     }
 
     private fun copyAssetToTempFile(assetName: String): File {
-        val ctx = InstrumentationRegistry.getInstrumentation().context
-        val tmp = File.createTempFile("upload-test-", ".m4a", ctx.cacheDir)
-        ctx.assets.open(assetName).use { input ->
+        val instrumentation = InstrumentationRegistry.getInstrumentation()
+        // Assets are packaged with the test APK; cache dir lives under the app APK.
+        val testCtx = instrumentation.context
+        val appCtx = instrumentation.targetContext
+        val tmp = File.createTempFile("upload-test-", ".m4a", appCtx.cacheDir)
+        testCtx.assets.open(assetName).use { input ->
             tmp.outputStream().use { output -> input.copyTo(output) }
         }
         return tmp