chore: remove debugging infrastructure after permission fixes

Removes temporary debugging docs and excessive logging that were added to diagnose and fix permission modal issues.

Cleaned up:
- Deleted DEBUGGING.md (temporary troubleshooting guide)
- Deleted FIXES-2026-02-06.md (temporary fix summary)
- Removed debug logging from all Rust modules

src-tauri/src/temp_manager.rs

@@ -77,8 +77,8 @@ impl TempFileManager {
             for file_path in files {
                 if file_path.exists() {
                     if let Err(e) = fs::remove_file(&file_path) {
-                        eprintln!(
-                            "Warning: Failed to remove temp file {:?}: {}",
+                        tracing::warn!(
+                            "Failed to remove temp file {:?}: {}",
                             file_path, e
                         );
                     }
@@ -115,7 +115,7 @@ impl TempFileManager {
             let path = entry.path();
             if path.is_file() && !tracked_files.contains(&path) {
                 if let Err(e) = fs::remove_file(&path) {
-                    eprintln!("Warning: Failed to remove orphaned file {:?}: {}", path, e);
+                    tracing::warn!("Failed to remove orphaned file {:?}: {}", path, e);
                 } else {
                     cleaned_count += 1;
                 }