feat(core): 重构词法分析器流接口并迁移至 core 库

将 lexer_stream 抽象为 core_stream，统一运行时核心组件的输入流模型。
移除了旧的 `lexer_stream.h` 定义，并将其功能完整迁移至 `core_stream.h` 中。
更新了内存流实现以适配新的 core_stream 接口，并修复部分资源释放问题。
同时调整日志模块包含方式，增强模块间解耦能力。

此变更影响词法分析器对输入流的操作方式，所有涉及 stream 的类型与函数均已替换为 core 前缀版本。
测试用例同步更新并验证通过。

runtime/libcore/src/stream.c

@@ -0,0 +1,101 @@
+#include <core_log.h>
+#include <core_stream.h>
+
+// 内存流的具体实现结构
+static usize read_buf(core_stream_t* _stream, char* buffer, usize count) {
+    Assert(buffer != null && buffer != null);
+    core_mem_stream_t* stream = (core_mem_stream_t*)_stream;
+
+    usize remaining = stream->data_length - stream->curr_pos;
+    usize to_read = (remaining < count) ? remaining : count;
+
+    if (to_read > 0) {
+        smcc_memcpy(buffer, stream->data + stream->curr_pos, to_read);
+        stream->curr_pos += to_read;
+    } else {
+        LOG_WARN("Reading past end of stream [maybe count is too large or negative?]");
+    }
+
+    return to_read;
+}
+
+static int peek_char(core_stream_t* _stream) {
+    Assert(_stream != null);
+    core_mem_stream_t* stream = (core_mem_stream_t*)_stream;
+
+    // 如果已经到达末尾，返回EOF
+    if (stream->peek_pos >= stream->data_length) {
+        return core_stream_eof; // EOF
+    }
+
+    return (int)(unsigned char)stream->data[stream->peek_pos++];
+}
+
+static int next_char(core_stream_t* _stream) {
+    Assert(_stream != NULL);
+    core_mem_stream_t* stream = (core_mem_stream_t*)_stream;
+
+    // 如果已经到达末尾，返回EOF
+    if (stream->curr_pos >= stream->data_length) {
+        return core_stream_eof; // EOF
+    }
+    
+    unsigned char ch = stream->data[stream->curr_pos++];
+    if (stream->peek_pos < stream->curr_pos) {
+        stream->peek_pos = stream->curr_pos;
+    }
+    return (int)ch;
+}
+
+static void reset_char(core_stream_t* _stream) {
+    Assert(_stream != NULL);
+    core_mem_stream_t* stream = (core_mem_stream_t*)_stream;
+
+    stream->peek_pos = stream->curr_pos;
+}
+
+static void free_stream(core_stream_t* _stream) {
+    Assert(_stream != null);
+    core_mem_stream_t* stream = (core_mem_stream_t*)_stream;
+
+    // FIXME maybe double free?
+    cstring_free(&stream->stream.name);
+
+    if (stream->owned) {
+        smcc_free((void*)stream->data);
+    }
+}
+
+core_stream_t* core_mem_stream_init(core_mem_stream_t* stream, const char* data, usize length, cbool need_copy) {
+    if (stream == null || data == NULL || length == 0) {
+        LOG_ERROR("param error");
+        return null;
+    }
+
+    stream->owned = need_copy;
+    if (need_copy) {
+        char* buf = (char*)smcc_malloc(length);
+        if (buf == null) {
+            LOG_ERROR("malloc error");
+            return null;
+        }
+
+        smcc_memcpy(buf, data, length);
+        stream->data = buf;
+    } else {
+        stream->data = data;
+    }
+    stream->data_length = length;
+    stream->curr_pos = 0;
+    stream->peek_pos = 0;
+
+    stream->stream.name = cstring_from_cstr("mem_stream");
+    
+    stream->stream.read_buf = read_buf;
+    stream->stream.peek_char = peek_char;
+    stream->stream.next_char = next_char;
+    stream->stream.reset_char = reset_char;
+    stream->stream.free_stream = free_stream;
+
+    return (void*)stream;
+}