feat: add internal ZCLAW kernel crates to git tracking

crates/zclaw-runtime/src/lib.rs

@@ -0,0 +1,19 @@
+//! ZCLAW Runtime
+//!
+//! LLM drivers, tool system, and agent loop implementation.
+
+pub mod driver;
+pub mod tool;
+pub mod loop_runner;
+pub mod loop_guard;
+pub mod stream;
+
+// Re-export main types
+pub use driver::{
+    LlmDriver, CompletionRequest, CompletionResponse, ContentBlock, StopReason,
+    ToolDefinition, DriverConfig, AnthropicDriver, OpenAiDriver, GeminiDriver, LocalDriver,
+};
+pub use tool::{Tool, ToolRegistry, ToolContext};
+pub use loop_runner::{AgentLoop, AgentLoopResult, LoopEvent};
+pub use loop_guard::{LoopGuard, LoopGuardConfig, LoopGuardResult};
+pub use stream::{StreamEvent, StreamSender};