Fix word wrap in transcript editor

- Add min-width: 0 to flex container (allows shrinking for wrap)
- Add overflow-x: hidden to prevent horizontal scroll
- Add white-space: pre-wrap to segment text

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/lib/components/TranscriptEditor.svelte

@@ -272,7 +272,9 @@
 <style>
   .transcript-editor {
     flex: 1;
+    min-width: 0;
     overflow-y: auto;
+    overflow-x: hidden;
     padding: 1rem;
     background: #16213e;
     border-radius: 8px;
@@ -319,6 +321,7 @@
   .segment-text {
     line-height: 1.6;
     padding-left: 0.75rem;
+    white-space: pre-wrap;
     word-wrap: break-word;
     overflow-wrap: break-word;
   }