Refresh app icons and support Illustrator SVG exports

[andre487]

Changes

Update the launcher and store icons from the revised Illustrator artwork and retain the separate square, round and status SVG sources, alongside editable Illustrator files.

Replace the generator's assumptions about specific SVG IDs and transforms with the SVG importer bundled with the existing Android Gradle Plugin. Preserve nested groups and clipping paths, and enforce RGB output for store PNGs.

Samsung previews now use a white background by default; --transparent preserves transparency for both PNG and SVG output. Document the export workflow and add regression coverage.

Validation

• Branding generator: 4 tests passed, including complete export and reproducibility.
• Samsung preview: 5 tests passed, including white and transparent backgrounds.
• Debug APK builds successfully; installation and launch were verified on Message487_API_35 during development.

APK artifacts

• Download debug APK — signed with the disposable Android debug key
• Download unsigned release APK — verified unsigned

Built from commit 324e753e by CI run #93.
Artifacts expire after 14 days. Neither APK uses the Message487 release key.