feat(quality): A4 — L2 Pro premium judge (8 dims, gpt-4o, Pro-gated, opt-in)

config.py

@@ -91,6 +91,19 @@ class Config:
     # Hard ceiling on the L1 call (seconds). Anything longer is a skip.
     QUALITY_L1_TIMEOUT_SEC = float(os.getenv("QUALITY_L1_TIMEOUT_SEC", "8.0"))
 
+    # ============== Quality Layer (L2 — Pro tier) ==============
+    # Track A4 of the dev plan — STRONGER LLM judge (8 dimensions).
+    # Gated to Pro+ plans in the route. Default off everywhere.
+    # Cost: ~$0.005–$0.02/job (gpt-4o) or ~$0.001/job (gpt-4o-mini).
+    # Set QUALITY_L2_TIER_GATE=false to allow L2 for free tier too.
+    QUALITY_L2_ENABLED = os.getenv("QUALITY_L2_ENABLED", "false").lower() == "true"
+    QUALITY_L2_LOG_ONLY = os.getenv("QUALITY_L2_LOG_ONLY", "true").lower() == "true"
+    QUALITY_L2_SAMPLE_SIZE = int(os.getenv("QUALITY_L2_SAMPLE_SIZE", "15"))
+    QUALITY_L2_MIN_CHUNKS = int(os.getenv("QUALITY_L2_MIN_CHUNKS", "20"))
+    QUALITY_L2_TIMEOUT_SEC = float(os.getenv("QUALITY_L2_TIMEOUT_SEC", "20.0"))
+    # When true, only Pro+ plans can use L2. Otherwise, all plans can.
+    QUALITY_L2_TIER_GATE = os.getenv("QUALITY_L2_TIER_GATE", "true").lower() == "true"
+
 
     # ============== API Configuration ==============
     API_TITLE = "Document Translation API"