tweak: lower minPlayers for low-pop server

- BloodBrothers: 20 → 10 players
- Vampire: 20 → 5 players
- SubVampire: 15 → 5 players

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Resources/Prototypes/_Wega/GameRules/roundstart.yml

@@ -4,7 +4,7 @@
   id: BloodBrothers
   components:
   - type: GameRule
-    minPlayers: 20
+    minPlayers: 10
   - type: BloodBrotherRule
     requiredObjectives:
     - BloodBrotherSharedEscapeObjective
@@ -29,7 +29,7 @@
   id: Vampire
   components:
   - type: GameRule
-    minPlayers: 20
+    minPlayers: 5
   - type: VampireRule
   - type: AntagObjectives
     objectives:

Resources/Prototypes/_Wega/GameRules/subgamemodes.yml

@@ -21,7 +21,7 @@
   id: SubVampire
   components:
   - type: GameRule
-    minPlayers: 15
+    minPlayers: 5
   - type: AntagSelection
     agentName: vampire-round-end-name
     definitions: