phase 7-8 完成 + warmup 修复 + 产物结构化重组

主要内容：
- Phase 8 PROMOTE: finalist #1 (trial #324) registry 条目，自动生成
- Optuna objective warmup bug 修复 (shared/optimizer/objective.py)
- studies/ 目录按用途重组为 optuna/ + finalists/ + features/ 三层
- reports/ 加入 Optuna 中文 dashboard (5 主图 + 18 slice + 15 contour)
- 新增 PROJECT_GUIDE.md 项目说明文档
- 新增 build_registry_entry.py / build_optuna_dashboard.py / build_feature_datasets.py
- .gitignore: 允许提交 studies/*.db (Optuna DB) 和 reports/*.html (MT5 + dashboard)

shared/mt5_pipeline/set_gen.py

@@ -17,6 +17,9 @@ from pathlib import Path
 from typing import Any, Mapping
 
 SET_FILE_ENCODING = "utf-16-le"
+# MT5's Strategy Tester silently ignores .set files without a UTF-16-LE BOM.
+# Python's "utf-16-le" codec does NOT emit a BOM, so prepend one explicitly.
+UTF16_LE_BOM = b"\xff\xfe"
 
 
 @dataclass
@@ -68,4 +71,4 @@ def write_set_file(
     if extra_lines:
         lines.extend(extra_lines)
     text = "\n".join(lines) + "\n"
-    out.write_bytes(text.encode(SET_FILE_ENCODING))
+    out.write_bytes(UTF16_LE_BOM + text.encode(SET_FILE_ENCODING))