feat: add stella-callgraph-node for JavaScript/TypeScript call graph extraction

- Implemented a new tool `stella-callgraph-node` that extracts call graphs from JavaScript/TypeScript projects using Babel AST.
- Added command-line interface with options for JSON output and help.
- Included functionality to analyze project structure, detect functions, and build call graphs.
- Created a package.json file for dependency management.

feat: introduce stella-callgraph-python for Python call graph extraction

- Developed `stella-callgraph-python` to extract call graphs from Python projects using AST analysis.
- Implemented command-line interface with options for JSON output and verbose logging.
- Added framework detection to identify popular web frameworks and their entry points.
- Created an AST analyzer to traverse Python code and extract function definitions and calls.
- Included requirements.txt for project dependencies.

chore: add framework detection for Python projects

- Implemented framework detection logic to identify frameworks like Flask, FastAPI, Django, and others based on project files and import patterns.
- Enhanced the AST analyzer to recognize entry points based on decorators and function definitions.

tests/StellaOps.Router.Gateway.Tests/RouterNodeConfigValidationTests.cs

@@ -0,0 +1,40 @@
+using FluentAssertions;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+using StellaOps.Router.Gateway.Configuration;
+using StellaOps.Router.Gateway.DependencyInjection;
+using Xunit;
+
+namespace StellaOps.Router.Gateway.Tests;
+
+public sealed class RouterNodeConfigValidationTests
+{
+    [Fact]
+    public void RouterNodeConfig_WhenRegionMissing_ThrowsOptionsValidationException()
+    {
+        var services = new ServiceCollection();
+        services.AddRouterGatewayCore();
+
+        using var provider = services.BuildServiceProvider();
+
+        var act = () => provider.GetRequiredService<IOptions<RouterNodeConfig>>().Value;
+
+        act.Should().Throw<OptionsValidationException>();
+    }
+
+    [Fact]
+    public void RouterNodeConfig_WhenRegionProvided_GeneratesNodeIdIfMissing()
+    {
+        var services = new ServiceCollection();
+        services.AddRouterGatewayCore();
+        services.Configure<RouterNodeConfig>(c => c.Region = "test");
+
+        using var provider = services.BuildServiceProvider();
+
+        var config = provider.GetRequiredService<IOptions<RouterNodeConfig>>().Value;
+
+        config.Region.Should().Be("test");
+        config.NodeId.Should().StartWith("gw-test-");
+        config.NodeId.Should().HaveLength("gw-test-".Length + 8);
+    }
+}