feat: add session deletion with per-provider cleanup and path safety

Add delete_session Tauri command dispatching to provider-specific deletion
logic for all 5 providers (Claude, Codex, Gemini, OpenCode, OpenClaw).
Includes path traversal protection via canonicalize + starts_with validation,
session ID verification against file contents, frontend confirmation dialog
with optimistic cache updates, i18n keys (zh/en/ja), and component tests.

src-tauri/src/commands/session_manager.rs

@@ -57,3 +57,20 @@ pub async fn launch_session_terminal(
 
     Ok(true)
 }
+
+#[tauri::command]
+pub async fn delete_session(
+    providerId: String,
+    sessionId: String,
+    sourcePath: String,
+) -> Result<bool, String> {
+    let provider_id = providerId.clone();
+    let session_id = sessionId.clone();
+    let source_path = sourcePath.clone();
+
+    tauri::async_runtime::spawn_blocking(move || {
+        session_manager::delete_session(&provider_id, &session_id, &source_path)
+    })
+    .await
+    .map_err(|e| format!("Failed to delete session: {e}"))?
+}