Baseline: full tree snapshot after git repository loss

The previous .git directory was found gutted (only info/ remained), so
history is unrecoverable locally. This commit restores version control
with the tree exactly as it stands: the working app, the preview-tracks
launcher on the artist hero, the scrollable-track-previews design bundle
(docs + approved mockups), and the Phase 0 validation artifacts.

.gitignore

@@ -0,0 +1,5 @@
+target/
+node_modules/
+dist/
+src-tauri/gen/
+*.log