feat: organizer Android app and token-gated upload API

Replace Syncthing as the product upload path with a share-target app
and POST /api/jobs. Web UI live-polls job progress.

Co-authored-by: Cursor <cursoragent@cursor.com>

android/build.gradle.kts

@@ -0,0 +1,6 @@
+plugins {
+    id("com.android.application") version "8.7.3" apply false
+    id("org.jetbrains.kotlin.android") version "2.0.21" apply false
+    id("org.jetbrains.kotlin.plugin.compose") version "2.0.21" apply false
+    id("org.jetbrains.kotlin.plugin.serialization") version "2.0.21" apply false
+}