fix: proxy uses undici ProxyAgent for fetch, schedule moved to .env, verbose redeem logging

- Fix proxy: native fetch needs undici ProxyAgent with dispatcher option
  (https-proxy-agent only works with axios, not Node's built-in fetch)
- Move schedule from hardcoded to .env: SNIPER_SCHEDULE_BTC=19:40-22:40,03:40-06:10
- Add verbose logging to redeemSniperPositions for debugging
- Config dynamically reads all SNIPER_SCHEDULE_* env vars

.env.example

@@ -148,6 +148,14 @@ SNIPER_PRICE=0.01
 # At $0.01/share: 5 shares = $0.05 per side, $0.10 per market
 SNIPER_SHARES=5
 
+# ── Sniper Session Schedule (all times UTC+8) ──────────────
+# Format: HH:MM-HH:MM,HH:MM-HH:MM (comma-separated sessions)
+# Assets without a schedule entry are always active.
+SNIPER_SCHEDULE_BTC=19:40-22:40,03:40-06:10
+SNIPER_SCHEDULE_ETH=11:40-15:40,16:40-19:40
+SNIPER_SCHEDULE_SOL=09:40-12:40,21:40-23:40
+SNIPER_SCHEDULE_XRP=18:40-20:40,08:40-09:50
+
 # ─────────────────────────────────────────────
 # PROXY (Polymarket API only, NOT Polygon RPC)
 # Supports HTTP/HTTPS/SOCKS5 proxies