refactor(java): modularize Java detection and management system

- Split monolithic java.rs (1089 lines) into focused modules
  - detection: Java installation discovery
  - validation: Version validation and requirements checking
  - priority: Installation selection priority logic
  - provider: Java download provider trait
  - providers: Provider implementations (Adoptium)
  - persistence: Cache and catalog management
- Add java_path_override field to Instance struct for per-instance Java configuration
- Export JavaInstallation at core module level

This refactoring improves maintainability and prepares for multi-vendor Java provider support.

Reviewed-by: Claude Sonnet 4.5

1 files changed, 3 insertions, 0 deletions

diff --git a/src-tauri/src/core/instance.rs b/src-tauri/src/core/instance.rs
index e7746b2..e842ec9 100644
--- a/src-tauri/src/core/instance.rs
+++ b/src-tauri/src/core/instance.rs
@@ -34,6 +34,7 @@ pub struct Instance {
     pub jvm_args_override: Option<String>,  // JVM参数覆盖（可选）
     #[serde(default)]
     pub memory_override: Option<MemoryOverride>, // 内存设置覆盖（可选）
+    pub java_path_override: Option<String>, // 实例级Java路径覆盖（可选）
 }
 
 /// Memory settings override for an instance
@@ -127,6 +128,7 @@ impl InstanceState {
             mod_loader_version: None,
             jvm_args_override: None,
             memory_override: None,
+            java_path_override: None,
         };
 
         let mut config = self.instances.lock().unwrap();
@@ -283,6 +285,7 @@ impl InstanceState {
             last_played: None,
             jvm_args_override: source_instance.jvm_args_override.clone(),
             memory_override: source_instance.memory_override.clone(),
+            java_path_override: source_instance.java_path_override.clone(),
         };
 
         self.update_instance(new_instance.clone())?;