fix(trend): surface DCA block reasons and ensure gate_bot poll thread

Log poll exceptions, diagnose live-trading and mark-price blocks on the trend page, start background monitors on app import, and add /api/trend_poll_status for debugging.

Co-authored-by: Cursor <cursoragent@cursor.com>

crypto_monitor_gate_bot/app.py

@@ -5270,11 +5270,27 @@ def background_task():
 
                 check_roll_monitors(_roll_cfg)
             check_order_monitors()
-        except:
-            pass
+        except Exception as e:
+            print(f"[background_task] error: {e}", flush=True)
         time.sleep(MONITOR_POLL_SECONDS)
 
 
+_BG_MONITORS_LOCK = threading.Lock()
+_BG_MONITORS_STARTED = False
+
+
+def _ensure_background_monitors_started():
+    global _BG_MONITORS_STARTED
+    with _BG_MONITORS_LOCK:
+        if _BG_MONITORS_STARTED:
+            return
+        _BG_MONITORS_STARTED = True
+        threading.Thread(
+            target=background_task, daemon=True, name="gate-bot-monitors"
+        ).start()
+        print("[startup] background monitor thread started", flush=True)
+
+
 # ====================== 登录路由 ======================
 @app.route("/login", methods=["GET", "POST"])
 def login():
@@ -5400,12 +5416,26 @@ def render_main_page(page="trade"):
         "SELECT * FROM trend_pullback_plans WHERE status='active' ORDER BY id DESC"
     ).fetchall()
     trend_plans = []
+    trend_dca_probes = []
+    _trend_cfg = app.extensions.get("strategy_trend_cfg")
     for r in trend_plans_raw:
         try:
-            trend_plans.append(enrich_active_trend_plan_row(r))
+            enriched = enrich_active_trend_plan_row(r)
+            trend_plans.append(enriched)
         except Exception as e:
             print(f"[render_main_page] enrich trend plan: {e}")
-            trend_plans.append(row_to_dict(r))
+            enriched = row_to_dict(r)
+            trend_plans.append(enriched)
+        if _trend_cfg and page in ("strategy", "strategy_trend", "strategy_roll"):
+            try:
+                from strategy_trend_register import summarize_trend_dca_probe
+
+                probe = summarize_trend_dca_probe(_trend_cfg, r)
+                trend_dca_probes.append(probe)
+                if isinstance(enriched, dict):
+                    enriched["dca_probe"] = probe
+            except Exception as e:
+                print(f"[render_main_page] trend dca probe: {e}")
     preview_snapshots = []
     if page == "records":
         try:
@@ -5511,6 +5541,8 @@ def render_main_page(page="trade"):
         manual_min_planned_rr=MANUAL_MIN_PLANNED_RR,
         can_trade=can_trade,
         trend_plans=trend_plans,
+        trend_dca_probes=trend_dca_probes,
+        live_trading_enabled=LIVE_TRADING_ENABLED,
         preview_snapshots=preview_snapshots,
         exchange_sync_from_label=(EXCHANGE_POSITION_SYNC_FROM_BJ or "最近90天"),
         trend_pullback_dca_legs=TREND_PULLBACK_DCA_LEGS,
@@ -8017,6 +8049,35 @@ def strategy_trend_page():
     return redirect(f"/strategy?{qs}" if qs else "/strategy")
 
 
+@app.route("/api/trend_poll_status")
+@login_required
+def api_trend_poll_status():
+    from strategy_trend_register import (
+        build_trend_config,
+        get_trend_poll_state,
+        summarize_trend_dca_probe,
+    )
+
+    cfg = app.extensions.get("strategy_trend_cfg") or build_trend_config(
+        sys.modules[__name__]
+    )
+    conn = get_db()
+    probes = []
+    for r in conn.execute(
+        "SELECT * FROM trend_pullback_plans WHERE status='active' ORDER BY id DESC"
+    ).fetchall():
+        probes.append(summarize_trend_dca_probe(cfg, r))
+    conn.close()
+    return jsonify(
+        {
+            "poll": get_trend_poll_state(),
+            "probes": probes,
+            "live_trading_enabled": LIVE_TRADING_ENABLED,
+            "monitor_poll_seconds": MONITOR_POLL_SECONDS,
+        }
+    )
+
+
 @app.route("/strategy/roll")
 @login_required
 def strategy_roll_page():
@@ -8035,9 +8096,9 @@ install_strategy_trading(
 app.extensions["strategy_trend_cfg"] = build_trend_config(sys.modules[__name__])
 
 _purge_key_monitors_if_full_margin()
+_ensure_background_monitors_started()
 
 
 # 启动
 if __name__ == "__main__":
-    threading.Thread(target=background_task, daemon=True).start()
     app.run(host=HOST, port=PORT, debug=DEBUG)