feat(search): rank results by match quality and split TV/People groups

Neither search backend orders by *where* the query matched, so a mid-word hit
could outrank a prefix one — typing "parks" surfaced "Sparks of Love" above
"Parks and Recreation".

Add `domain/search_rank.rs`, which sorts by match position (prefix →
word-start → mid-word substring → no name match), then by media kind so a
container outranks its own contents. The sort is stable, so each backend's own
relevance still breaks ties it was never overruled on. `repository_search`
applies it to both the instant cache result and the merged cache+server union,
so the list does not reshuffle when server results land. Ranking lives in Rust
because "a better match" is domain vocabulary, not presentation.

On the frontend, the combined `tvShows` result group splits into separate
Shows and Episodes groups so a show no longer competes with its own episodes
for a slot, and a People group is added so searching an actor's name reaches
their bio. A stored `tvShows` order expands in place, keeping the position an
upgrading user chose for it.

src-tauri/src/commands/repository.rs

@@ -12,6 +12,7 @@ use serde::{Deserialize, Serialize};
 use tauri::{AppHandle, Emitter, State};
 use uuid::Uuid;
 
+use crate::domain::rank_search_results;
 use crate::jellyfin::HttpClient;
 use crate::repository::{
     types::*, HybridRepository, MediaRepository, OfflineRepository, OnlineRepository,
@@ -409,7 +410,7 @@ pub async fn repository_search(
 
     // Phase 1: instant local results from the cache (downloaded content) so the
     // UI can render immediately while the server is still being queried.
-    let cache_result = repo
+    let mut cache_result = repo
         .search_cache_only(&query, options.clone())
         .await
         .unwrap_or_else(|e| {
@@ -420,6 +421,12 @@ pub async fn repository_search(
             }
         });
 
+    // Neither backend orders by *where* the query matched, so a mid-word hit
+    // ("Sparks" for "parks") can outrank a prefix hit ("Parks and Recreation").
+    // Both phases are ranked with the same rules so the list does not reshuffle
+    // when the server results land.
+    rank_search_results(&mut cache_result.items, &query);
+
     // Phase 2: query the live server in the background, merge with the cache,
     // and push the union to the frontend via a `search-event`. Tagged with
     // `request_id` so the frontend can discard results from superseded queries.
@@ -428,7 +435,11 @@ pub async fn repository_search(
     tauri::async_runtime::spawn(async move {
         match repo_bg.search_server_only(&query, options).await {
             Ok(server_result) => {
-                let merged = HybridRepository::merge_search_results(cache_for_merge, server_result);
+                let mut merged =
+                    HybridRepository::merge_search_results(cache_for_merge, server_result);
+                // Rank the union, not each half: a server-only prefix match must
+                // be able to outrank a cached mid-word one.
+                rank_search_results(&mut merged.items, &query);
                 let event = SearchUpdateEvent {
                     request_id,
                     result: merged,