feat: improve status feedback with detailed messages and colors

- Added color-coded status indicators (success, error, streaming)
- Detailed status messages for all operations
- Success messages auto-reset to "Ready" after 2 seconds
- Error messages show context for debugging
- Status feedback for: API calls, character switching, history clearing,
  configuration saving, message generation, and regeneration
- Smooth color transitions for better UX

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

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

src/styles.css

@@ -732,6 +732,7 @@ body {
 .status-text {
   font-size: 12px;
   color: var(--text-secondary);
+  transition: color 0.2s ease;
 }
 
 .status-text.streaming {
@@ -739,6 +740,14 @@ body {
   animation: pulse 2s ease-in-out infinite;
 }
 
+.status-text.error {
+  color: #ef4444;
+}
+
+.status-text.success {
+  color: #22c55e;
+}
+
 @keyframes pulse {
   0%, 100% {
     opacity: 1;