rename: Android is Inkwell — package, applicationId, uniffi class, assets

Step 4 of milestone 481 (Scribe note 5071: a full rename).

- namespace and applicationId com.fabledsword.inkwell; the Kotlin package moves
  with them, and ktlint re-sorted the imports the rename reordered (checked
  locally with CI's ktlint 1.4.0 and detekt 1.23.7, both clean)
- uniffi: class Inkwell in com.fabledsword.inkwell.core, InkwellApplication,
  InkwellTheme, Theme.Inkwell, log tags, prefs and work names, client agent
  inkwell-android
- the lane publishes inkwell.apk / inkwell-android.json; fetch-clients,
  guard-forward, publish-release and write-manifest read the same names

A new applicationId is a new app. The old ThoughtSync app keeps its own store
and stays installed beside it. Notes cross over by syncing, and the old app is
then removed by hand.

Kept: the signing keyAlias is still "thoughtsync". It names the key inside the
existing keystore, and the key, and so the certificate, are unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/app/src/main/res/values/colors.xml

@@ -2,6 +2,6 @@
 <resources>
     <!-- The product's brand colour, same value the web app's manifest and
          <meta name="theme-color"> already use. One source of truth for "what
-         colour is ThoughtSync" across the three surfaces. -->
+         colour is Inkwell" across the three surfaces. -->
     <color name="ic_launcher_background">#F5C518</color>
 </resources>

android/app/src/main/res/values/themes.xml

@@ -6,5 +6,5 @@
       truth in XML — the same reason the desktop reads its live theme rather
       than hardcoding a window colour.
     -->
-    <style name="Theme.ThoughtSync" parent="android:Theme.Material.NoActionBar" />
+    <style name="Theme.Inkwell" parent="android:Theme.Material.NoActionBar" />
 </resources>