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/TestSingle/main.swift

@@ -0,0 +1,46 @@
+import Foundation
+import MarkBase
+
+print("\n=== 测试 NaN Bug ===\n")
+
+let modelPath = "./models/E4B-MarkBase"
+print("加载模型...")
+let engine = try MarkBaseEngine(autoCompile: true)
+let model = try E4BModel(modelDir: modelPath, engine: engine, maxContextLength: 512)
+let tokenizer = try TokenizerFactory.load(modelDir: modelPath)
+print("✓ 模型加载完成\n")
+
+// 测试 prompt encoding
+let prompt = "Hello"
+print("Prompt: '\(prompt)'")
+let promptTokens = tokenizer.encode(text: prompt)
+print("Tokens: \(promptTokens)")
+print("Token details:")
+for (i, tokenId) in promptTokens.enumerated() {
+    let raw = tokenizer.rawToken(for: tokenId) ?? "nil"
+    print("  [\(i)] ID=\(tokenId) → '\(raw)'")
+}
+
+print("\n=== 测试 Forward Pass ===\n")
+
+// 测试第一个 token 的 forward pass
+var lastLogits: [Float] = []
+for (position, tokenId) in promptTokens.enumerated() {
+    print("Forward pass: tokenId=\(tokenId), position=\(position)")
+    lastLogits = try model.forward(tokenId: tokenId, position: position)
+    
+    // 检查 NaN
+    let hasNaN = lastLogits.contains { $0.isNaN }
+    let nanCount = lastLogits.filter { $0.isNaN }.count
+    let maxVal = lastLogits.max() ?? 0
+    let minVal = lastLogits.min() ?? 0
+    
+    print("  Logits: count=\(lastLogits.count), hasNaN=\(hasNaN), nanCount=\(nanCount)")
+    print("  Stats: max=\(maxVal), min=\(minVal)")
+    if nanCount < 10 {
+        print("  Sample (first 20): \(lastLogits.prefix(20))")
+    }
+    print()
+}
+
+print("=== 测试完成 ===")