feat: Add .slnx to C#/F# LSP root detection (#11928)

packages/opencode/src/lsp/server.ts

@@ -732,7 +732,7 @@ export namespace LSPServer {
 
   export const CSharp: Info = {
     id: "csharp",
-    root: NearestRoot([".sln", ".csproj", "global.json"]),
+    root: NearestRoot([".slnx", ".sln", ".csproj", "global.json"]),
     extensions: [".cs"],
     async spawn(root) {
       let bin = Bun.which("csharp-ls", {
@@ -772,7 +772,7 @@ export namespace LSPServer {
 
   export const FSharp: Info = {
     id: "fsharp",
-    root: NearestRoot([".sln", ".fsproj", "global.json"]),
+    root: NearestRoot([".slnx", ".sln", ".fsproj", "global.json"]),
     extensions: [".fs", ".fsi", ".fsx", ".fsscript"],
     async spawn(root) {
       let bin = Bun.which("fsautocomplete", {