feat: enhance project-specific slash commands management

- Add scopeFilter prop to SlashCommandsManager for filtering by scope
- Replace browser confirm() with proper delete confirmation dialog
- Fix slash_command_delete to handle project commands with project_path param
- Add Slash Commands tab to ProjectSettings as the default tab
- Add Commands button to ClaudeCodeSession for quick access
- Improve error handling and user feedback for delete operations
- Better UI text when showing project-specific commands only

src-tauri/src/commands/slash_commands.rs

@@ -416,11 +416,25 @@ pub async fn slash_command_save(
 
 /// Delete a slash command
 #[tauri::command]
-pub async fn slash_command_delete(command_id: String) -> Result<String, String> {
+pub async fn slash_command_delete(command_id: String, project_path: Option<String>) -> Result<String, String> {
     info!("Deleting slash command: {}", command_id);
     
-    // Get the command to find its file path
-    let command = slash_command_get(command_id.clone()).await?;
+    // First, we need to determine if this is a project command by parsing the ID
+    let is_project_command = command_id.starts_with("project-");
+    
+    // If it's a project command and we don't have a project path, error out
+    if is_project_command && project_path.is_none() {
+        return Err("Project path required to delete project commands".to_string());
+    }
+    
+    // List all commands (including project commands if applicable)
+    let commands = slash_commands_list(project_path).await?;
+    
+    // Find the command by ID
+    let command = commands
+        .into_iter()
+        .find(|cmd| cmd.id == command_id)
+        .ok_or_else(|| format!("Command not found: {}", command_id))?;
     
     // Delete the file
     fs::remove_file(&command.file_path)