feat(file-explorer): add parallel thumbnail loading and file preview

- Implement parallel thumbnail queue (2 concurrent) for gallery view
- Add BottomSheetModal file preview with 80% snap point
- Add pull-to-refresh for directory listings
- Fix image loading race conditions with Set-based in-flight tracking

Also includes:
- message-input: add Cmd+Shift+D dictation toggle shortcut
- message: update user message bubble to darker zinc color
- Add PRODUCTION.md deployment guide

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/app/src/components/message.tsx

@@ -45,7 +45,7 @@ const userMessageStylesheet = StyleSheet.create((theme) => ({
     paddingHorizontal: theme.spacing[4],
   },
   bubble: {
-    backgroundColor: theme.colors.primary,
+    backgroundColor: theme.colors.muted,
     borderRadius: theme.borderRadius["2xl"],
     borderTopRightRadius: theme.borderRadius.sm,
     paddingHorizontal: theme.spacing[4],
@@ -53,7 +53,7 @@ const userMessageStylesheet = StyleSheet.create((theme) => ({
     maxWidth: "80%",
   },
   text: {
-    color: theme.colors.primaryForeground,
+    color: theme.colors.foreground,
     fontSize: theme.fontSize.lg,
     lineHeight: 24,
   },