feat: 添加 README，更新 .gitignore，移除 JE-Skin/eskin-finger-sdk

- 添加 README.md 项目文档
- 更新 .gitignore 排除 JE-Skin/、eskin-finger-sdk/ 及构建产物
- 从 git 跟踪中移除 JE-Skin 和 eskin-finger-sdk

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/matrix.rs

@@ -11,8 +11,6 @@ const MIN_BOARD_PADDING: f32 = 2.6;
 const MAX_BOARD_PADDING: f32 = 6.8;
 const MATRIX_OFFSET_Y: f32 = -2.4;
 const MATRIX_OFFSET_Z: f32 = 12.0;
-const HEIGHT_SCALE: f32 = 10.6;
-const BASE_HEIGHT: f32 = 0.12;
 const CAMERA_FOV: f32 = 36.0;
 const CAMERA_DISTANCE_MIN: f32 = 30.0;
 const CAMERA_DISTANCE_MAX: f32 = 122.0;
@@ -87,14 +85,13 @@ pub fn glyph_world_position(
     pressure: f32,
 ) -> ([f32; 4], f32) {
     let normalized = pressure.clamp(0.0, 1.0);
-    let height = BASE_HEIGHT + normalized.powf(0.9) * HEIGHT_SCALE;
     let x = (col as f32 - cols as f32 / 2.0 + 0.5) * layout.cell_spacing;
     let z = (row as f32 - rows as f32 / 2.0 + 0.5) * layout.cell_spacing;
 
     (
         [
             x,
-            MATRIX_OFFSET_Y + height + layout.label_float_offset,
+            MATRIX_OFFSET_Y + layout.label_float_offset,
             MATRIX_OFFSET_Z + z,
             1.0,
         ],