refactor(integrations): move MB location and genre helpers to qbz-integrations

Pure-logic move of two helper modules out of src-tauri/src/musicbrainz/
into the qbz-integrations crate, where the MusicBrainzClient and DTOs
already live:

  src-tauri/src/musicbrainz/location_discovery.rs
    -> crates/qbz-integrations/src/musicbrainz/location.rs
  src-tauri/src/musicbrainz/genre_normalization.rs
    -> crates/qbz-integrations/src/musicbrainz/genre.rs

The functions exposed are unchanged: extract_metadata,
compute_affinity_score, build_scene_cache_key, format_life_span_date
(from location); normalize_genre, is_broad_genre, extract_affinity_seeds,
genre_summary (from genre). Imports in src-tauri/src/commands_v2/
integrations.rs are repointed to the new home; the legacy file
declarations are removed from src-tauri/src/musicbrainz/mod.rs. No
behavior change.

Unblocks the Slint side from reaching the same helpers via qbz-core
without depending on src-tauri.

cc

crates/qbz-integrations/src/musicbrainz/genre.rs

@@ -5,7 +5,7 @@
 
 use std::collections::HashSet;
 
-use qbz_integrations::musicbrainz::{AffinitySeeds, Tag};
+use super::{AffinitySeeds, Tag};
 
 /// Tags that provide no useful genre/scene signal
 const NOISY_TAGS: &[&str] = &[

crates/qbz-integrations/src/musicbrainz/location.rs

@@ -7,8 +7,11 @@
 
 use std::collections::HashSet;
 
-use super::genre_normalization::{extract_affinity_seeds, normalize_genre};
-use qbz_integrations::musicbrainz::*;
+use super::genre::{extract_affinity_seeds, normalize_genre};
+use super::{
+    AffinitySeeds, Area, ArtistFullResponse, ArtistLocation, ArtistMetadata, ArtistType, LifeSpan,
+    LocationPrecision,
+};
 
 /// Extract artist metadata from the full MB response
 pub fn extract_metadata(response: &ArtistFullResponse) -> ArtistMetadata {

crates/qbz-integrations/src/musicbrainz/mod.rs

@@ -31,5 +31,8 @@ mod models;
 #[cfg(feature = "cache")]
 pub mod cache;
 
+pub mod genre;
+pub mod location;
+
 pub use client::{MusicBrainzClient, MusicBrainzConfig};
 pub use models::*;

src-tauri/Cargo.lock

@@ -5121,6 +5121,7 @@ dependencies = [
  "qbz-models",
  "qbz-player",
  "qbz-qobuz",
+ "serde",
  "serde_json",
  "thiserror 2.0.18",
  "tokio",

src-tauri/src/commands_v2/integrations.rs

@@ -552,7 +552,7 @@ pub async fn v2_musicbrainz_get_artist_metadata(
     drop(client);
 
     // Extract metadata using the location discovery module (now uses V2 types)
-    let mut metadata = crate::musicbrainz::location_discovery::extract_metadata(&artist);
+    let mut metadata = qbz_integrations::musicbrainz::location::extract_metadata(&artist);
 
     // Resolve real country from begin_area hierarchy (MB's "country" field is
     // where the artist is active, not where they were born/formed)
@@ -606,10 +606,10 @@ pub async fn v2_discover_artists_by_location(
     runtime: State<'_, RuntimeManagerState>,
     app: tauri::AppHandle,
 ) -> Result<qbz_integrations::musicbrainz::LocationDiscoveryResponse, RuntimeError> {
-    use crate::musicbrainz::genre_normalization::{
+    use qbz_integrations::musicbrainz::genre::{
         extract_affinity_seeds, genre_summary, is_broad_genre,
     };
-    use crate::musicbrainz::location_discovery::{build_scene_cache_key, compute_affinity_score};
+    use qbz_integrations::musicbrainz::location::{build_scene_cache_key, compute_affinity_score};
     use qbz_integrations::musicbrainz::{
         AffinitySeeds, LocationCandidate, LocationDiscoveryResponse, Tag,
     };

src-tauri/src/musicbrainz/mod.rs

@@ -21,8 +21,6 @@ pub mod smart_playlists;
 
 pub use cache::{CacheStats, MusicBrainzCache, MusicBrainzCacheState};
 pub use client::{MusicBrainzClient, MusicBrainzConfig};
-pub mod genre_normalization;
-pub mod location_discovery;
 
 pub use models::{
     AffinitySeeds, AlbumAppearance, Area, AreaResult, AreaSearchResponse, ArtistBrowseResponse,