Add app source for F-Droid release (v1.0.6)

Adds the full Android source tree, Gradle wrapper, fastlane store
metadata and the fdroiddata build recipe so F-Droid can build from
source. README gains build instructions and an updated structure tree.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015g6ECVSKcBG8CJPrqC3G5o

app/src/main/res/drawable/ic_refresh.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="256"
+    android:viewportHeight="256">
+    <path
+        android:fillColor="#FFFFFFFF"
+        android:fillType="evenOdd"
+        android:pathData="M139.0,212.3L138.3,211.0L138.3,202.0L139.0,201.3L149.0,198.3L161.0,192.3L169.0,186.3L176.3,179.0L183.0,170.0L188.5,158.0L190.5,150.0L191.5,141.0L191.3,131.0L189.3,120.0L187.3,114.0L184.3,108.0L181.3,103.0L175.0,95.0L170.0,90.0L165.0,86.0L159.0,82.0L155.0,80.0L154.0,80.0L153.0,79.0L146.0,76.7L135.0,74.5L122.0,74.5L121.7,75.0L137.7,91.0L130.0,98.5L100.3,69.0L130.0,39.3L131.0,39.7L137.3,46.0L137.0,47.0L121.0,63.0L122.0,63.5L135.0,63.7L148.0,66.0L157.0,69.0L158.0,70.0L159.0,70.0L163.0,72.0L171.0,77.0L176.0,81.0L185.0,90.0L187.3,93.0L190.3,97.0L196.3,108.0L200.3,120.0L202.3,137.0L201.5,149.0L198.5,162.0L192.0,176.0L184.0,187.0L173.0,197.3L164.0,203.3L151.0,209.3L148.0,209.7L144.0,211.3L140.0,211.7ZM116.0,211.7L107.0,210.0L98.0,207.0L88.0,202.0L81.0,197.0L71.7,188.0L64.7,179.0L58.7,168.0L58.3,166.0L55.7,160.0L53.7,151.0L52.7,139.0L53.5,128.0L55.7,118.0L58.0,111.0L63.0,101.0L69.0,92.0L75.0,85.5L82.5,93.0L76.0,100.0L72.0,106.0L68.0,114.0L66.0,120.0L64.5,126.0L63.5,136.0L63.7,145.0L65.7,156.0L68.7,164.0L74.3,174.0L79.0,180.0L87.0,188.0L94.0,193.0L102.0,197.0L109.0,199.5L116.0,201.0L116.7,202.0L116.7,211.0Z" />
+</vector>