fix: correct success/failure toast message for batch conversions

Fixed bug where conversion success toast was always showing "all conversions failed"
even when conversions succeeded. The issue was that the completion message was checking
the local jobs array (which still had status: 'pending') instead of tracking actual
conversion results.

Now using local successCount and failureCount variables that are incremented during
the conversion loop to accurately reflect conversion outcomes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

components/converter/FileConverter.tsx

@@ -99,6 +99,10 @@ export function FileConverter() {
 
     setConversionJobs(jobs);
 
+    // Track success/failure counts
+    let successCount = 0;
+    let failureCount = 0;
+
     // Convert files sequentially
     for (let i = 0; i < jobs.length; i++) {
       const job = jobs[i];
@@ -145,6 +149,8 @@ export function FileConverter() {
 
         // Update job with result
         if (result.success && result.blob) {
+          successCount++;
+
           setConversionJobs((prev) =>
             prev.map((j, idx) => idx === i ? {
               ...j,
@@ -165,6 +171,8 @@ export function FileConverter() {
             result: result.blob,
           });
         } else {
+          failureCount++;
+
           setConversionJobs((prev) =>
             prev.map((j, idx) => idx === i ? {
               ...j,
@@ -175,6 +183,7 @@ export function FileConverter() {
           );
         }
       } catch (error) {
+        failureCount++;
         const errorMessage = error instanceof Error ? error.message : 'Unknown error';
 
         setConversionJobs((prev) =>
@@ -189,7 +198,6 @@ export function FileConverter() {
     }
 
     // Show completion message
-    const successCount = jobs.filter(j => j.status === 'completed').length;
     if (successCount === jobs.length) {
       addToast(`All ${jobs.length} files converted successfully!`, 'success');
     } else if (successCount > 0) {