feat: session filter, breakeven SL, daily loss limit, startup alert, multi-pair web

Bot improvements:
- Session filter (SESSION_FROM_UTC/TO_UTC) — backtest confirms 08-13 UTC optimal for XAU
- Breakeven SL management (BREAKEVEN_AT_RR) — disabled by default, hurts XAU momentum
- Daily loss limit circuit breaker (DAILY_LOSS_LIMIT_PCT)
- Telegram startup alert with symbol, session, risk, and balance
- MT5 modify_position (TRADE_ACTION_SLTP) support in mt5-client

Web updates:
- Version badge auto-fetched from GitHub Releases API
- GitHub icon link in Nav and footer
- Multi-pair general (not XAUUSDm-specific)
- BTCUSDm backtest results added, session params in params table
- Trades page uses rolling 90-day window instead of hardcoded date

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/app/page.tsx

@@ -11,8 +11,9 @@ export default function DashboardPage() {
           ARES Trading Bot
         </h1>
         <p className="text-[18px] text-ink-md leading-relaxed max-w-2xl mb-8">
-          M5 Momentum FVG scalper built in Rust. Targets Fair Value Gaps on XAUUSDm
-          with EMA-20 trend filter, automatic position sizing, and Telegram alerts.
+          Open-source algorithmic trading bot built in Rust. Momentum FVG scalper
+          with EMA trend filter, configurable session window, automatic position
+          sizing, and Telegram alerts — runs on any MT5 symbol.
         </p>
         <div className="flex gap-3 flex-wrap">
           <Link href="/trades"   className="btn-primary">View Trades</Link>