feat(notify): Telegram alerts on trade open and close

New module bot/notify/telegram.py — httpx async, fire-and-forget via
asyncio.create_task, swallows all errors so notifications never affect
trade execution.

Three alert types:
  📈/📉 TRADE ABIERTO  — direction, size, edge_net (in execute())
  ✅/❌  GANADO/PERDIDO — approx PnL (in close_position())
  🔒    LEGACY CLOSE   — recovered capital + reason (in close_legacy_position())

close_position() and close_legacy_position() gain an optional question=""
param so the message shows the market name instead of market_id.
bot/main.py updated to pass question= to close_legacy_position().

Credentials (TELEGRAM_BOT_TOKEN, TELEGRAM_CHAT_ID) read from env vars
injected via bot-secrets k8s secret.

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

bot/main.py

@@ -347,7 +347,7 @@ async def run_legacy_scan(
         log.warning("PAPER MODE: auto-closing %d CLOSE_RECOMMENDED position(s)...", n_close)
         for p in enriched:
             if p["recommendation"] == "CLOSE_RECOMMENDED":
-                recovered = await executor.close_legacy_position(p["market_id"], p["rec_reason"])
+                recovered = await executor.close_legacy_position(p["market_id"], p["rec_reason"], question=p["question"])
                 log.warning(
                     "  AUTO_CLOSED market=%s | $%.2f returned to cash | %s",
                     p["market_id"], recovered, p["question"][:60],