Update comments and instructions in .env.example

.env.example

@@ -131,12 +131,29 @@ LLM_MODEL=anthropic/claude-sonnet-4-5
 # Keys are rotated round-robin on every request — useful when you
 # have multiple accounts or want to spread rate-limit quota.
 #
+# Smart backoff: when a key gets a 429/402 response, it is temporarily
+# suspended so other keys handle traffic.
+#   Strike 1 → suspended for KEY_BLACKLIST_COOLDOWN_MS   (default 60 s)
+#   Strike 2 → suspended for KEY_BLACKLIST_COOLDOWN_MS × 4 (default 4 min)
+#   Strike 3 → suspended for 24 h  (quota likely exhausted — skipped all day)
+# A successful response resets the strike counter for that key.
+#
 # Pattern: <PROVIDER>_API_KEYS=key1,key2,key3
 # Fallback order: plural pool → singular key → LLM_API_KEY (optional)
 # Set false only if you want to disable global LLM_API_KEY fallback
 # across providers.
 LLM_API_KEY_FALLBACK_ENABLED=true
 #
+# Base backoff duration (ms) after the first 429 on a key (default: 60 s).
+# Increases exponentially on repeated failures.
+# KEY_BLACKLIST_COOLDOWN_MS=60000
+#
+# Number of consecutive 429/quota errors before a key is suspended for 24 h.
+# KEY_MAX_STRIKES=3
+#
+# Note: KIMI_API_KEYS and MOONSHOT_API_KEYS share the same API endpoint
+# (api.moonshot.cn) and are combined into one rotation pool automatically.
+#
 # Uncomment and fill in only the providers you use:
 #
 # ANTHROPIC_API_KEYS=sk-ant-key1,sk-ant-key2,sk-ant-key3
@@ -147,7 +164,8 @@ LLM_API_KEY_FALLBACK_ENABLED=true
 # KILOCODE_API_KEYS=key1,key2
 # OPENCODE_API_KEYS=key1,key2
 # ZAI_API_KEYS=key1,key2
-# MOONSHOT_API_KEYS=key1,key2
+# MOONSHOT_API_KEYS=key1,key2   # combines with KIMI_API_KEYS
+# KIMI_API_KEYS=key1,key2       # combines with MOONSHOT_API_KEYS
 # MINIMAX_API_KEYS=key1,key2
 # XIAOMI_API_KEYS=key1,key2
 # VOLCANO_ENGINE_API_KEYS=key1,key2