feat(core): 扩展 API、完善日志与代码文档规范

- 公开颜色过滤与字符集限制扩展 API，修复宏路径
- 库内打印替换为 tracing 日志，清理遗留废弃代码
- 补充核心逻辑单元测试与 crate 元数据
- 开启 missing_docs 并统一 rustfmt/clippy 格式

ddddocr-core/tests/api_surface.rs

@@ -0,0 +1,72 @@
+//! 外部视角 API 测试：验证颜色过滤与字符集限制扩展点对外可用。
+
+use std::borrow::Cow;
+
+use ddddocr_core::color_any_of;
+use ddddocr_core::{
+    CharRestrict, ColorFilter, ColorPreset, HsvRange, IdRestrict, OcrBuilder, TokenFilter, any_of,
+};
+
+#[test]
+fn color_filter_setter_accepts_owned_preset() {
+    let builder = OcrBuilder::new().color_filter(ColorPreset::Red);
+    let _ = builder;
+}
+
+#[test]
+fn color_any_of_macro_expands_and_collects() {
+    let ranges = color_any_of!(ColorPreset::Red, ColorPreset::Blue)
+        .collect_to_vec()
+        .expect("收集颜色区间失败")
+        .expect("应存在有效颜色区间");
+    // Red 两段 + Blue 一段
+    assert_eq!(ranges.len(), 3);
+}
+
+#[test]
+fn charset_restrict_setter_accepts_owned_restrict() {
+    let builder = OcrBuilder::new().charset_restrict(CharRestrict::Digit);
+    let _ = builder;
+}
+
+#[test]
+fn any_of_macro_expands_and_filters() {
+    let tokens: Vec<Cow<'static, str>> = vec![
+        Cow::Borrowed(""),
+        Cow::Borrowed("1"),
+        Cow::Borrowed("a"),
+        Cow::Borrowed("A"),
+    ];
+
+    let indices = any_of!(CharRestrict::Digit, CharRestrict::Lowercase)
+        .apply_to_charset(&tokens)
+        .expect("字符集应存在交集");
+    // 0 号 blank 放行 + 数字 '1' + 小写 'a'
+    assert_eq!(indices, vec![0, 1, 2]);
+}
+
+#[test]
+fn id_restrict_filters_by_index() {
+    let tokens: Vec<Cow<'static, str>> = vec![
+        Cow::Borrowed(""),
+        Cow::Borrowed("1"),
+        Cow::Borrowed("2"),
+        Cow::Borrowed("3"),
+    ];
+
+    let indices = IdRestrict::TopN(2)
+        .apply_to_charset(&tokens)
+        .expect("字符集应存在交集");
+    assert_eq!(indices, vec![0, 1]);
+}
+
+#[test]
+fn hsv_range_validate() {
+    let range = HsvRange::new((0, 50, 50), (10, 255, 255));
+    assert!(range.validate().is_ok());
+    assert!(
+        HsvRange::new((200, 0, 0), (255, 255, 255))
+            .validate()
+            .is_err()
+    );
+}