feat(hub): enrich AI coach with fund history, closed trades, and chat uploads

- Add 15-day fund snapshot store and /api/hub/account on all instances

- Summary includes yesterday/today trades, fund columns, and section 5 操作建议

- Chat context distinguishes empty positions from local monitors

- Support image/document attachments in AI chat

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

manual_trading_hub/hub_ai/client.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 
 import sys
 from pathlib import Path
+from typing import Optional, Sequence
 
 _REPO_ROOT = Path(__file__).resolve().parents[2]
 if str(_REPO_ROOT) not in sys.path:
@@ -15,6 +16,12 @@ def model_label() -> str:
     return ai_provider_label()
 
 
-def generate_text(*, system: str, user: str, temperature: float) -> str:
+def generate_text(
+    *,
+    system: str,
+    user: str,
+    temperature: float,
+    images_b64: Optional[Sequence[str]] = None,
+) -> str:
     prompt = f"{system.strip()}\n\n---\n\n{user.strip()}"
-    return ai_generate(prompt, temperature=temperature)
+    return ai_generate(prompt, temperature=temperature, images_b64=images_b64)