fix(luna-tts): never vote for competitor side in random fallback

server/strategy.py

@@ -91,7 +91,11 @@ def decide(left: SideResult, right: SideResult, threshold: float = 0.80) -> Deci
     if right_is_comp:
         return Decision(action="vote_left",
                         reason=f"right 最高分为竞品 {right.top_speaker}({right.top_score:.4f}) → 投 left")
-    # Neither competitor — random
-    side = random.choice([left, right])
+    # Neither competitor qualifies → pick non-competitor side, random if both ok
+    non_comp_sides = [s for s in (left, right) if s.top_library != "competitor"]
+    if not non_comp_sides:
+        return Decision(action="skip",
+                        reason="双方最高分都来自竞品库 → 弃权")
+    side = random.choice(non_comp_sides)
     return Decision(action=f"vote_{side.label}",
                     reason=f"双方无我方/大厂/竞品 ≥ {threshold} → 随机投{side.label}")