Start the setup wizard blank and add a Run setup again button

The first-run seed no longer inserts the original vendor's name, address, contact
details, PAN or bank account; the wizard now starts empty and requires a name and
state. Settings > Data gets a Run setup again button that clears the onboarded flag.
Re-running the wizard keeps the active invoice series unless the prefix or padding
changes. The sample logo moves out of public/ so it no longer ships in the app.

src-tauri/src/logo.rs

@@ -213,7 +213,7 @@ fn clean_alpha(img: &mut RgbaImage) {
 }
 
 /// Keep 64 levels per channel (steps of about 4/255, invisible in print). Anti-aliasing and encoder
-/// noise of +-1 otherwise makes flat colours incompressible: the Test Vendor logo drops from 149 KB to 75 KB.
+/// noise of +-1 otherwise makes flat colours incompressible: a sample wordmark logo drops from 149 KB to 75 KB.
 fn quantize_colour(img: &mut RgbaImage) {
     for p in img.pixels_mut() {
         for c in 0..3 {
@@ -535,7 +535,7 @@ mod tests {
 
     #[test]
     fn sample_logo_is_trimmed_and_small() {
-        let path = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../public/brand/sample-wordmark-logo.png");
+        let path = std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../src/pdf/testing/fixtures/sample-wordmark-logo.png");
         let bytes = std::fs::read(path).unwrap();
         let out = process_logo(&bytes).unwrap();
         let m = &out.metrics;