fix: ensure permission/stats persist until explicit disconnect (#110)

Also includes cached tokens in cost calculations to provide more accurate billing estimates.

Reviewed-on: #110
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src-tauri/src/achievements.rs

@@ -2329,6 +2329,10 @@ mod tests {
             context_utilisation_percent: 0.0,
             potential_cache_hits: 0,
             potential_cache_savings_tokens: 0,
+            current_request_input: None,
+            current_request_output_chars: 0,
+            current_request_thinking_chars: 0,
+            current_request_tools: Vec::new(),
             achievements: AchievementProgress::new(),
         }
     }