feat(core): 建立 fund-lab 可运行基线

[变更性质]
- 本提交冻结当前可构建、可测试的应用基线，不包含 PostgreSQL 持久化。

[新增功能]
- 建立 F# Domain、API、Worker、Web 及测试项目。
- 增加 Bearer 认证、健康检查、账本领域模型和中文空状态页面。

[实现方案]
- 使用环境变量模板注入认证配置，并排除数据、凭证和构建产物。
- 保留 19 个 Domain 测试和 5 个 API 测试作为后续变更基准。

[影响范围]
- 为后续 3a PostgreSQL FOF 创建/读取切片提供可回滚基线。
- 当前仍不接入真实基金数据、真实交易或数据库。

1 files changed, 53 insertions, 0 deletions

diff --git a/src/FundLab.Api/App.fs b/src/FundLab.Api/App.fs
new file mode 100644
index 0000000..44628ab
--- /dev/null
+++ b/src/FundLab.Api/App.fs
@@ -0,0 +1,53 @@
+namespace FundLab.Api
+
+open System
+open Giraffe
+open Microsoft.AspNetCore.Http
+
+type EmptyPortfolioResponse =
+    {
+        status: string
+        message: string
+    }
+
+module App =
+    let private unauthorized : HttpHandler =
+        setStatusCode 401
+        >=> setHttpHeader "WWW-Authenticate" "Bearer"
+        >=> text "Unauthorized"
+
+    let private requireBearer (next: HttpFunc) (ctx: HttpContext) =
+        let expectedToken =
+            Environment.GetEnvironmentVariable("FUND_LAB_AUTH_TOKEN")
+            |> Option.ofObj
+            |> Option.defaultValue ""
+
+        let authorizationHeader = ctx.Request.Headers.Authorization.ToString()
+
+        match Authentication.authorize expectedToken authorizationHeader with
+        | AuthDecision.Authorized -> next ctx
+        | AuthDecision.Unauthorized -> unauthorized next ctx
+
+    let private health : HttpHandler =
+        json ({
+            service = "fund-lab-api"
+            status = "ok"
+        } : HealthResponse)
+
+    let private emptyPortfolio : HttpHandler =
+        json {
+            status = "empty"
+            message = "尚未创建基金/尚未选择投资"
+        }
+
+    let createApplication () : HttpHandler =
+        choose [
+            GET >=> route "/health" >=> health
+            subRoute "/api" (
+                requireBearer
+                >=> choose [
+                    GET >=> route "/portfolio/summary" >=> emptyPortfolio
+                ]
+            )
+            setStatusCode 404 >=> text "Not Found"
+        ]