Add max_file_size_mb and high_only logic to scanning process:

- Implement `max_file_size_mb` to restrict files for scanning based on size.
- Refactor `high_only` handling to modify `min_severity` in `Config`.
- Update `ScannerConfig` to use `Option<u64>` for optional size limits.
- Remove redundant `high_only` parameter from `scan::handle` function.
- Improve batch processing in `walk` for efficient file scanning.

src/commands/mod.rs

@@ -5,16 +5,19 @@ pub mod clean;
 
 use crate::cli::Commands;
 use std::path::Path;
+use crate::patterns::Severity;
 use crate::utils::config::Config;
 
 pub fn handle_command(
     command: Commands,
     database_dir: &Path,
-    config: &Config
+    config: &mut Config
 ) -> Result<(), Box<dyn std::error::Error>> {
     match command {
         Commands::Scan { path, no_index, rebuild_index, format, high_only } => {
-            scan::handle(&path, no_index, rebuild_index, format, high_only, database_dir, config)
+            if high_only { config.scanner.min_severity = Severity::High };
+            
+            scan::handle(&path, no_index, rebuild_index, format, database_dir, config)
         }
         Commands::Index { action } => {
             index::handle(action, database_dir, config)