feat(ipc): typed bindings for library catalog/genre browse commands

First vertical slice of the tauri-specta rollout: annotate two psysonic-library
browse-metadata commands (library_get_catalog_year_bounds,
library_get_genre_album_counts) with #[specta::specta] and derive specta::Type on
their DTOs (CatalogYearBoundsDto, GenreAlbumCountDto), then add them to
collect_commands!. bindings.ts now carries their typed signatures + DTO shapes
(serde camelCase carried through). Non-breaking: generate_handler! stays the live
handler and nothing imports the bindings yet.

Both DTOs are i64-free (i32/u32/String), so no BigInt handling is needed here —
that convention is decided when the first i64 DTO is annotated. Generated
src/generated is excluded from eslint (its runtime helper uses `any`); tsc still
type-checks bindings.ts.

src-tauri/crates/psysonic-library/Cargo.toml

@@ -11,6 +11,7 @@ psysonic-core = { path = "../psysonic-core" }
 psysonic-integration = { path = "../psysonic-integration" }
 
 tauri = { version = "2" }
+specta = { version = "=2.0.0-rc.25", features = ["derive"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 rusqlite = { version = "0.40", features = ["bundled"] }

src-tauri/crates/psysonic-library/src/browse_support.rs

@@ -99,6 +99,7 @@ pub(crate) fn catalog_year_bounds_for_server(
 
 /// Min/max album years from the local track catalog (for Albums browse filter spinners).
 #[tauri::command]
+#[specta::specta]
 pub fn library_get_catalog_year_bounds(
     runtime: State<'_, LibraryRuntime>,
     server_id: String,
@@ -150,6 +151,7 @@ pub(crate) fn genre_album_counts_for_server(
 
 /// Distinct album counts per track genre — same grouping as genre album browse.
 #[tauri::command]
+#[specta::specta]
 pub fn library_get_genre_album_counts(
     runtime: State<'_, LibraryRuntime>,
     server_id: String,

src-tauri/crates/psysonic-library/src/dto.rs

@@ -382,7 +382,7 @@ pub struct PlaySessionYearBoundsDto {
 }
 
 /// Min/max `year` from indexed tracks for a server (Albums year filter UI).
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, specta::Type)]
 #[serde(rename_all = "camelCase")]
 pub struct CatalogYearBoundsDto {
     pub min_year: Option<i32>,
@@ -390,7 +390,7 @@ pub struct CatalogYearBoundsDto {
 }
 
 /// Per-genre album/track totals from the local track catalog (Genres cloud + browse).
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, specta::Type)]
 #[serde(rename_all = "camelCase")]
 pub struct GenreAlbumCountDto {
     pub value: String,