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.

crates/metadata/examples/discography_audit.rs

@@ -0,0 +1,124 @@
+//! Broad discography audit over the PRODUCTION artist pipeline.
+//!
+//! Runs `catalog_artist` (Deezer + Apple supplement, dedup, edition folding)
+//! plus the deferred `catalog_artist_identity` MusicBrainz pass for each
+//! requested artist, and prints one JSON object per artist (JSONL) with the
+//! final album rows and MB type hints — exactly the data the artist page
+//! files into tabs. An external analyzer replicates the frontend's category
+//! rules over this dump to flag duplicates and misfiled releases.
+//!
+//! Usage:
+//!   cargo run -p metadata --example discography_audit -- "Artist" ...
+//!   cargo run -p metadata --example discography_audit -- --broad
+
+use metadata::MetadataClient;
+use std::sync::Arc;
+
+const BROAD_ARTISTS: [&str; 44] = [
+    "Weezer",
+    "Radiohead",
+    "Queen",
+    "The Beatles",
+    "Taylor Swift",
+    "Beyoncé",
+    "Coldplay",
+    "Nirvana",
+    "Fleetwood Mac",
+    "Elton John",
+    "David Bowie",
+    "Pink Floyd",
+    "Led Zeppelin",
+    "Bob Dylan",
+    "Miles Davis",
+    "Daft Punk",
+    "deadmau5",
+    "Fatboy Slim",
+    "Bonobo",
+    "Four Tet",
+    "Calvin Harris",
+    "Aphex Twin",
+    "The Chemical Brothers",
+    "Crazy P",
+    "Moby",
+    "Björk",
+    "Depeche Mode",
+    "Kanye West",
+    "Kendrick Lamar",
+    "Eminem",
+    "Drake",
+    "Travis Scott",
+    "Hans Zimmer",
+    "John Williams",
+    "Danny Elfman",
+    "Ludwig Göransson",
+    "Nine Inch Nails",
+    "MGMT",
+    "Panda Bear",
+    "Tame Impala",
+    "Mac DeMarco",
+    "Gorillaz",
+    "Metallica",
+    "ABBA",
+];
+
+#[tokio::main]
+async fn main() {
+    let mut requested: Vec<String> = std::env::args().skip(1).collect();
+    if requested.iter().any(|a| a == "--broad") {
+        requested = BROAD_ARTISTS.iter().map(|s| s.to_string()).collect();
+    }
+    if requested.is_empty() {
+        eprintln!("pass artist names or --broad");
+        std::process::exit(2);
+    }
+
+    let client = Arc::new(MetadataClient::new());
+    for name in requested {
+        let search = client.catalog_search(&name).await;
+        let want = normalize(&name);
+        let artist = search
+            .artists
+            .iter()
+            .filter(|a| normalize(&a.name) == want)
+            .max_by_key(|a| a.fans)
+            .or_else(|| search.artists.first());
+        let Some(artist) = artist else {
+            println!(
+                "{}",
+                serde_json::json!({ "requested": name, "error": "not_found" })
+            );
+            continue;
+        };
+        let id = artist.id;
+        let display = artist.name.clone();
+        let fans = artist.fans;
+        let page = client.catalog_artist(id).await;
+        let Some(page) = page else {
+            println!(
+                "{}",
+                serde_json::json!({ "requested": name, "artist_id": id, "error": "page_failed" })
+            );
+            continue;
+        };
+        let identity = client.catalog_artist_identity(id, &display).await;
+        println!(
+            "{}",
+            serde_json::json!({
+                "requested": name,
+                "artist_id": id,
+                "artist": display,
+                "fans": fans,
+                "albums": page.albums,
+                "type_hints": identity.type_hints,
+                "identity_albums": identity.albums,
+            })
+        );
+    }
+}
+
+fn normalize(s: &str) -> String {
+    s.to_lowercase()
+        .chars()
+        .filter(|c| c.is_alphanumeric())
+        .collect()
+}