fix: add missing append_body flag to Android and Windows release workflows

Ensures changelog is preserved when these workflows upload to releases. Previously, these workflows would overwrite the auto-generated changelog with only the install notes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: pliablepixels

.github/workflows/build-android.yml

@@ -83,6 +83,7 @@ jobs:
         with:
           generate_release_notes: true
           body_path: .github/workflows/_RELEASE_NOTE_INSERT.md
+          append_body: true
           files: |
             dist/android/*.apk
             dist/android/*.aab

.github/workflows/build-windows.yml

@@ -61,6 +61,7 @@ jobs:
         with:
           generate_release_notes: true
           body_path: .github/workflows/_RELEASE_NOTE_INSERT.md
+          append_body: true
           files: |
             app/src-tauri/target/release/bundle/msi/*.msi
             app/src-tauri/target/release/bundle/nsis/*.exe