Partner commanders: Partner, Partner—<variant>, Partner with, Background, Doctor

A Commander/Brawl deck can now have two commanders when their abilities
allow it. Partner abilities are parsed from oracle text (Scryfall's keyword
list files every "Partner—Survivors"-style variant under plain "Partner"),
and a second search box offers only cards that can pair with the commander.
The legality check accepts a valid pair and checks color identity against
both; suggestions and decklist import/export handle both commanders.

Closes #4

src-tauri/src/commands.rs

@@ -329,6 +329,32 @@ pub fn set_deck_commander(db: Db, deck_id: i64, oracle_id: Option<String>) -> Re
         .map_err(|e| e.to_string())
 }
 
+/// Set the deck's commanders — one, or a partner pair — first is primary.
+#[tauri::command]
+pub fn set_deck_commanders(db: Db, deck_id: i64, oracle_ids: Vec<String>) -> Res<()> {
+    let s = db.lock().unwrap();
+    let ids: Vec<&str> = oracle_ids.iter().map(String::as_str).collect();
+    s.catalog()?
+        .set_deck_commanders(deck_id, &ids)
+        .map_err(|e| e.to_string())
+}
+
+/// Name search narrowed to cards that could partner with the given commander.
+/// Searches wide before filtering, since most name matches won't qualify.
+#[tauri::command]
+pub fn search_partners(
+    db: Db,
+    commander_oracle_id: String,
+    query: String,
+    limit: usize,
+) -> Res<Vec<CardRef>> {
+    let s = db.lock().unwrap();
+    let candidates = s.index()?.search(&query, 500);
+    s.catalog()?
+        .partner_candidates(&commander_oracle_id, candidates, limit)
+        .map_err(|e| e.to_string())
+}
+
 #[tauri::command]
 pub fn set_deck_card(
     db: Db,

src-tauri/src/lib.rs

@@ -103,6 +103,8 @@ pub fn run() {
             commands::duplicate_deck,
             commands::set_deck_format,
             commands::set_deck_commander,
+            commands::set_deck_commanders,
+            commands::search_partners,
             commands::set_deck_card,
             commands::deck_contents,
             commands::suggest_cards,