feat(app): 接入 AKShare 行情采集、净值查询与前端净值曲线

[变更性质]
- 本提交完成 3b 行情闭环：真实 AKShare 搜索与净值采集、PostgreSQL 持久化、鉴权 API 与 Fable 前端净值曲线展示。

[新增功能]
- API 新增 /api/instruments/search、/api/instruments/{code}/nav 与 nav/refresh 接口，经 Bearer 鉴权调用 AKShare Python 采集器并幂等落库。
- 前端提供基金搜索、精确代码选择、历史净值刷新/重读与 SVG 折线图，token 变更即清空私有结果并失效在途请求。

[实现方案]
- MarketData 以 requiredProperty 校验采集器 payload，净值观测按 (code, nav_date) 幂等 upsert 并保留来源与哈希。
- 前端以 requestId 序列守卫 SearchCompleted/SearchFailed/NavCompleted/NavFailed，TokenChanged 同时递增 searchSeq/navSeq 拒绝过期响应；边界解码兼容 F# option 的 {"case":"Some"} 线格式。

[影响范围]
- 新增 FundLab.Web.Tests（边界解码、序列失效、图表纯函数共 8 项），扩展 API 测试至 20 项；vite dev 代理 /api 至本地 API。
- 真实 AKShare 端到端依赖本机 akshare 环境，由负责人另行验收；本提交不包含 docs/overnight-progress.md 的现有修改。

1 files changed, 171 insertions, 0 deletions

diff --git a/src/FundLab.Api/akshare_collector.py b/src/FundLab.Api/akshare_collector.py
new file mode 100644
index 0000000..f988a61
--- /dev/null
+++ b/src/FundLab.Api/akshare_collector.py
@@ -0,0 +1,171 @@
+#!/usr/bin/env python3
+"""Small raw-data adapter for the AKShare endpoints used by Fund Lab."""
+
+import argparse
+import datetime as dt
+import json
+import re
+import sys
+from decimal import Decimal, InvalidOperation
+
+import akshare as ak
+import pandas as pd
+
+
+SCHEMA_VERSION = "fund-lab.akshare.v1"
+
+
+def collected_at():
+    return dt.datetime.now(dt.timezone.utc).isoformat().replace("+00:00", "Z")
+
+
+def source_revision():
+    return f"akshare-{getattr(ak, '__version__', 'unknown')}/eastmoney"
+
+
+def is_missing(value):
+    try:
+        return bool(pd.isna(value))
+    except (TypeError, ValueError):
+        return False
+
+
+def text(value):
+    if is_missing(value):
+        return None
+    value = str(value).strip()
+    return value or None
+
+
+def fund_code(value):
+    value = text(value)
+    if value is None:
+        return None
+    if value.isdigit() and len(value) < 6:
+        value = value.zfill(6)
+    return value if re.fullmatch(r"\d{6}", value) else None
+
+
+def decimal_text(value):
+    value = text(value)
+    if value is None:
+        return None
+    try:
+        return format(Decimal(value), "f")
+    except InvalidOperation:
+        return None
+
+
+def date_text(value):
+    if is_missing(value):
+        return None
+    if isinstance(value, (dt.datetime, dt.date)):
+        return value.strftime("%Y-%m-%d")
+    parsed = pd.to_datetime(value, errors="coerce")
+    if pd.isna(parsed):
+        return None
+    return parsed.strftime("%Y-%m-%d")
+
+
+def search(query):
+    query = query.strip()
+    if not query:
+        raise ValueError("search query cannot be empty")
+
+    frame = ak.fund_name_em()
+    query_lower = query.casefold()
+    rows = []
+
+    for _, row in frame.iterrows():
+        code = fund_code(row.get("基金代码"))
+        name = text(row.get("基金简称"))
+        pinyin = text(row.get("拼音缩写"))
+        full_pinyin = text(row.get("拼音全称"))
+
+        if code is None or name is None:
+            continue
+
+        searchable = [code, name, pinyin or "", full_pinyin or ""]
+        if not any(query_lower in value.casefold() for value in searchable):
+            continue
+
+        rows.append(
+            {
+                "code": code,
+                "name": name,
+                "fund_type": text(row.get("基金类型")),
+                "rank": 0 if code == query else (1 if name == query else 2),
+            }
+        )
+
+    rows.sort(key=lambda item: (item.pop("rank"), item["code"]))
+    return {
+        "schema_version": SCHEMA_VERSION,
+        "operation": "search",
+        "source": "akshare",
+        "source_revision": source_revision(),
+        "collected_at": collected_at(),
+        "instruments": rows[:100],
+    }
+
+
+def nav(code):
+    if not re.fullmatch(r"\d{6}", code):
+        raise ValueError("fund code must contain exactly six digits")
+
+    frame = ak.fund_open_fund_info_em(
+        symbol=code,
+        indicator="单位净值走势",
+        period="成立来",
+    )
+    observations = []
+
+    for _, row in frame.iterrows():
+        nav_date = date_text(row.get("净值日期"))
+        nav_value = decimal_text(row.get("单位净值"))
+        if nav_date is None or nav_value is None:
+            continue
+
+        observations.append(
+            {
+                "nav_date": nav_date,
+                "published_at": None,
+                "nav": nav_value,
+                "accumulated_nav": None,
+                "daily_return": decimal_text(row.get("日增长率")),
+            }
+        )
+
+    if not observations:
+        raise ValueError(f"AKShare returned no usable NAV observations for {code}")
+
+    return {
+        "schema_version": SCHEMA_VERSION,
+        "operation": "nav",
+        "source": "akshare",
+        "source_revision": source_revision(),
+        "collected_at": collected_at(),
+        "instrument": {"code": code},
+        "observations": observations,
+    }
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--operation", choices=("search", "nav"), required=True)
+    parser.add_argument("--query")
+    parser.add_argument("--code")
+    args = parser.parse_args()
+
+    try:
+        payload = search(args.query) if args.operation == "search" else nav(args.code)
+        json.dump(payload, sys.stdout, ensure_ascii=False, separators=(",", ":"))
+        sys.stdout.write("\n")
+        return 0
+    except Exception as error:
+        print(f"AKShare collector failed: {error}", file=sys.stderr)
+        return 2
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())