Stop auto-assigning the Captain when a ship is stolen

Completing Crew Objective 1 (Steal a Ship) no longer anoints the
highest-ranked Pi-Rat as Captain (nor vacates the seat when the ship is
lost). Captaincy is now earned: the crew chooses one via the Captaincy
UI / set_captain and Crew Objective 2. Decoupled captaincy from crew_1
in toggle_objective, dropped the now-unused random import, and updated
test_captaincy_and_hand_sizes accordingly.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_game.py

@@ -357,20 +357,20 @@ def test_captaincy_and_hand_sizes(session):
     session.commit()
     assert crud.calculate_max_hand_size(p3, game.players, game.captain_player_id) == 4
 
-    # Completing Crew Objective 1 (Steal a Ship) makes the highest-ranked Pi-Rat the Captain
+    # Stealing a ship does NOT auto-assign a Captain — the crew must earn and
+    # choose one. Completing Crew Objective 1 leaves the captaincy vacant.
     crud.toggle_objective(session, game.id, p1.id, "crew_1", True)
     session.refresh(game)
-    assert game.captain_player_id in (p2.id, p3.id)
-    captain = crud.get_player(session, game.captain_player_id)
-    assert crud.is_player_captain(captain, game)
-    # Captain privilege: +1 hand size
-    assert crud.calculate_max_hand_size(captain, game.players, game.captain_player_id) == 5
-
-    # Losing the ship vacates the Captaincy
-    crud.toggle_objective(session, game.id, p1.id, "crew_1", False)
-    session.refresh(game)
     assert game.captain_player_id is None
 
+    # The crew chooses a Captain explicitly (via the Captaincy UI / set_captain).
+    crud.set_captain(session, game, p2.id)
+    session.refresh(game)
+    assert game.captain_player_id == p2.id
+    assert crud.is_player_captain(p2, game)
+    # Captain privilege: +1 hand size
+    assert crud.calculate_max_hand_size(p2, game.players, game.captain_player_id) == 5
+
 def test_captain_tax_on_failed_challenge(session):
     game, deep, (p2, p3) = make_scene_game(session, num_pirats=2)
     # p3 (rank 2) becomes captain