refactor: remove screenshot functionality and headless_chrome dependency

Remove the screenshot capture system and associated UI components to simplify the codebase.

- Remove screenshot.rs command module and related functionality
- Remove headless_chrome dependency from Cargo.toml
- Update Cargo.lock to reflect dependency changes
- Remove screenshot handlers and UI from WebviewPreview component
- Clean up screenshot-related API calls and imports
- Remove camera icon and capture controls from preview interface

This reduces bundle size and eliminates an underutilized feature.

src-tauri/src/main.rs

@@ -33,7 +33,7 @@ use commands::mcp::{
     mcp_read_project_config, mcp_remove, mcp_reset_project_choices, mcp_save_project_config,
     mcp_serve, mcp_test_connection,
 };
-use commands::screenshot::{capture_url_screenshot, cleanup_screenshot_temp_files};
+
 use commands::usage::{
     get_session_stats, get_usage_by_date_range, get_usage_details, get_usage_stats,
 };
@@ -160,9 +160,7 @@ fn main() {
             mcp_reset_project_choices,
             mcp_get_server_status,
             mcp_read_project_config,
-            mcp_save_project_config,
-            capture_url_screenshot,
-            cleanup_screenshot_temp_files
+            mcp_save_project_config
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");