v2: Initial clean branch with unit tests + CI/CD pipeline

- Started from ac75faa (initial E4B-MarkBase integration)
- Kept Sources/ (all engine code) + Package.swift + .gitignore
- Removed all ad-hoc tests, documentation, scripts, Python files
- Added Tests/00_Unit/ (MathTest, TokenizerTest, SamplerTest)
- Added .gitea/workflows/ci.yaml (build + unit tests + lint)
- Added Scripts/check_resources.sh (memory-aware test runner)
- Added Tests/Manifest.json (resource requirements for all tests)
- Focus: 4-bit quantized models only

Sources/MarkBaseServer/APIServer.swift

@@ -0,0 +1,31 @@
+import MarkBase
+
+/// Entry point for MarkBase API server
+/// Usage: swift run G12BServer [model_dir] [port] [model_id] [--benchmark]
+@main
+public struct ServerMain {
+    public static func main() async throws {
+        let args = CommandLine.arguments
+        
+        // Check for benchmark mode
+        if args.contains("--benchmark") {
+            let modelDir = args.count > 2 ? args[1] : "./model"
+            let modelName = args.count > 3 ? args[2] : "markbase"
+            
+            var benchmark = PerformanceBenchmark(modelDir: modelDir, modelName: modelName)
+            try await benchmark.run()
+            return
+        }
+        
+        let modelDir = args.count > 1 ? args[1] : "./model"
+        let port = args.count > 2 ? Int(args[2]) ?? 8080 : 8080
+        let modelId = args.count > 3 ? args[3] : "markbase-12b"
+        
+        print("\n╔═════════════════════════════════════════════╗")
+        print("║      MarkBase API Server                    ║")
+        print("╚═════════════════════════════════════════════╝\n")
+        
+        let server = try MarkBaseServer(modelDir: modelDir, modelId: modelId)
+        try await server.start(port: port)
+    }
+}