fixes: GCP dependency and add flakes

.config/dotnet-tools.json

@@ -0,0 +1,13 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "csharpier": {
+      "version": "1.2.3",
+      "commands": [
+        "csharpier"
+      ],
+      "rollForward": false
+    }
+  }
+}

flake.nix

@@ -0,0 +1,46 @@
+{
+
+  description = ".NET 9 Development Environment";
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    { nixpkgs, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+          # Allow unfree packages if you use specific proprietary dotnet tools
+          config.allowUnfree = true;
+        };
+
+        # Define the .NET SDK version you want to use
+        dotnetSdk = pkgs.dotnetCorePackages.sdk_9_0-bin;
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          # Tools included in the environment
+          packages = [
+            pkgs.zsh
+            dotnetSdk
+
+            # --- Optional: IDE Tooling ---
+            pkgs.netcoredbg # Debugger for .NET Core
+            pkgs.roslyn-ls # LSP for VS Code / Emacs / Vim
+          ];
+
+          # Environment variables
+          # 1. Essential: Tell dotnet tools where to find the SDK
+          DOTNET_ROOT = "${dotnetSdk}";
+
+          # 3. Add .NET tools to PATH (e.g., dotnet-ef installed locally)
+          #          shellHook = ''
+          #          export PATH="$PATH:$HOME/.dotnet/tools"
+          #          '';
+        };
+      }
+    );
+}

src/Fluent.Brighter.GoogleCloud/Fluent.Brighter.GoogleCloud.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks>$(BrighterTargetFrameworks)</TargetFrameworks>
+        <TargetFrameworks>$(BrighterFrameworkAndCoreTargetFrameworks)</TargetFrameworks>
         <Nullable>enable</Nullable>
         <GenerateDocumentationFile>true</GenerateDocumentationFile>
         <Title>Fluent Brighter Google Cloud Platform Integration</Title>