feat(live2d): implement OpenGL ES 2.0 rendering backend with EGL support

- Add `gl.rs` for OpenGL ES 2.0 and EGL context management.
- Introduce `mod.rs` to organize Live2D plugin modules.
- Create `model.rs` for loading and managing Cubism models, including parameter handling and drawable data extraction.
- Implement shader compilation and rendering context setup for Live2D models.

src/plugins/live2d/assets.rs

@@ -0,0 +1,155 @@
+//! 资源管理：model3.json 解析 + PNG 纹理加载
+
+use anyhow::{anyhow, Context, Result};
+use serde::Deserialize;
+use std::path::{Path, PathBuf};
+
+/// model3.json 中的 Groups 条目
+#[derive(Deserialize, Clone, Debug)]
+pub struct ModelGroup {
+    #[serde(rename = "Target")]
+    pub target: String,
+    #[serde(rename = "Name")]
+    pub name: String,
+    #[serde(rename = "Ids")]
+    pub ids: Vec<String>,
+}
+
+/// model3.json 文件引用
+#[derive(Deserialize, Clone, Debug)]
+pub struct FileReferences {
+    #[serde(rename = "Moc")]
+    pub moc: String,
+    #[serde(rename = "Textures", default)]
+    pub textures: Vec<String>,
+    #[serde(rename = "Physics", default)]
+    pub physics: Option<String>,
+    #[serde(rename = "Pose", default)]
+    pub pose: Option<String>,
+    #[serde(rename = "DisplayInfo", default)]
+    pub display_info: Option<String>,
+}
+
+/// model3.json 根结构
+#[derive(Deserialize, Clone, Debug)]
+pub struct Model3Json {
+    #[serde(rename = "Version")]
+    pub version: i32,
+    #[serde(rename = "FileReferences")]
+    pub file_references: FileReferences,
+    #[serde(rename = "Groups", default)]
+    pub groups: Vec<ModelGroup>,
+}
+
+impl Model3Json {
+    /// 从文件解析
+    pub fn from_path(path: &Path) -> Result<Self> {
+        let text = std::fs::read_to_string(path)
+            .with_context(|| format!("读取 model3.json 失败: {}", path.display()))?;
+        let json: Model3Json = serde_json::from_str(&text)
+            .with_context(|| format!("解析 model3.json 失败: {}", path.display()))?;
+        Ok(json)
+    }
+
+    /// 获取 LipSync 参数 ID 列表
+    pub fn lip_sync_ids(&self) -> Vec<String> {
+        self.groups
+            .iter()
+            .find(|g| g.target == "Parameter" && g.name == "LipSync")
+            .map(|g| g.ids.clone())
+            .unwrap_or_else(|| vec!["ParamMouthOpenY".to_string()])
+    }
+
+    /// 获取 EyeBlink 参数 ID 列表
+    pub fn eye_blink_ids(&self) -> Vec<String> {
+        self.groups
+            .iter()
+            .find(|g| g.target == "Parameter" && g.name == "EyeBlink")
+            .map(|g| g.ids.clone())
+            .unwrap_or_else(|| {
+                vec!["ParamEyeLOpen".to_string(), "ParamEyeROpen".to_string()]
+            })
+    }
+}
+
+/// 加载的纹理图像（RGBA）
+pub struct TextureImage {
+    pub width: u32,
+    pub height: u32,
+    pub rgba: Vec<u8>,
+}
+
+/// 加载 PNG 纹理（使用 image crate）
+pub fn load_texture(path: &Path) -> Result<TextureImage> {
+    let img = image::open(path)
+        .with_context(|| format!("加载纹理失败: {}", path.display()))?
+        .to_rgba8();
+    let width = img.width();
+    let height = img.height();
+    let rgba = img.into_raw();
+    Ok(TextureImage {
+        width,
+        height,
+        rgba,
+    })
+}
+
+/// 加载 model3.json 引用的所有纹理（返回按 texture_00, texture_01 顺序的列表）
+pub fn load_all_textures(
+    model3_dir: &Path,
+    file_refs: &FileReferences,
+) -> Result<Vec<TextureImage>> {
+    let mut textures = Vec::new();
+    for tex_rel in &file_refs.textures {
+        let tex_path = model3_dir.join(tex_rel);
+        let img = load_texture(&tex_path)?;
+        println!(
+            "[Live2D] 纹理加载: {} ({}x{})",
+            tex_rel, img.width, img.height
+        );
+        textures.push(img);
+    }
+    Ok(textures)
+}
+
+/// 解析 model3.json 并返回完整路径集
+pub struct ModelAssetPaths {
+    pub model3_json: PathBuf,
+    pub model3_dir: PathBuf,
+    pub moc3: PathBuf,
+    pub textures: Vec<PathBuf>,
+}
+
+/// 从 model3.json 相对路径（如 "haru/Haru.model3.json"）解析资源路径
+pub fn resolve_asset_paths(
+    live2d_base_dir: &Path,
+    model3_json_rel: &str,
+) -> Result<ModelAssetPaths> {
+    let model3_json = live2d_base_dir.join(model3_json_rel);
+    if !model3_json.exists() {
+        return Err(anyhow!(
+            "model3.json 不存在: {}",
+            model3_json.display()
+        ));
+    }
+    let model3_dir = model3_json
+        .parent()
+        .ok_or_else(|| anyhow!("无法获取 model3.json 的父目录"))?
+        .to_path_buf();
+
+    let model3 = Model3Json::from_path(&model3_json)?;
+    let moc3 = model3_dir.join(&model3.file_references.moc);
+    let textures = model3
+        .file_references
+        .textures
+        .iter()
+        .map(|t| model3_dir.join(t))
+        .collect();
+
+    Ok(ModelAssetPaths {
+        model3_json,
+        model3_dir,
+        moc3,
+        textures,
+    })
+}