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/stats.rs

@@ -618,7 +618,7 @@ pub async fn save_stats(app: &tauri::AppHandle, stats: &UsageStats) -> Result<()
 
     let persisted = PersistedStats::from(stats);
 
-    println!("Saving stats: {:?}", persisted);
+    tracing::info!("Saving stats: {:?}", persisted);
 
     store.set(
         "lifetime_stats",
@@ -626,32 +626,32 @@ pub async fn save_stats(app: &tauri::AppHandle, stats: &UsageStats) -> Result<()
     );
     store.save().map_err(|e| e.to_string())?;
 
-    println!("Stats saved successfully");
+    tracing::info!("Stats saved successfully");
     Ok(())
 }
 
 /// Load lifetime stats from persistent store
 pub async fn load_stats(app: &tauri::AppHandle) -> Option<PersistedStats> {
-    println!("Loading stats from store...");
+    tracing::info!("Loading stats from store...");
 
     let store = match app.store("stats.json") {
         Ok(s) => s,
         Err(e) => {
-            println!("Failed to open stats store: {}", e);
+            tracing::error!("Failed to open stats store: {}", e);
             return None;
         }
     };
 
     if let Some(stats_value) = store.get("lifetime_stats") {
-        println!("Found lifetime stats in store: {:?}", stats_value);
+        tracing::info!("Found lifetime stats in store: {:?}", stats_value);
         if let Ok(persisted) = serde_json::from_value::<PersistedStats>(stats_value.clone()) {
-            println!("Loaded lifetime stats successfully");
+            tracing::info!("Loaded lifetime stats successfully");
             return Some(persisted);
         } else {
-            println!("Failed to parse lifetime stats");
+            tracing::error!("Failed to parse lifetime stats");
         }
     } else {
-        println!("No lifetime stats found in store");
+        tracing::info!("No lifetime stats found in store");
     }
 
     None