refactor: extract consistent AppBar builder, remove icon from EVENT LOG title

- Add buildTracPulseAppBar() helper in lib/app_bar.dart
  - Reads backgroundColor/elevation from ThemeData.appBarTheme
  - Consistent back button (#9e9e9e, size 20) via Navigator.pop
  - Monospace title style (14px, weight 700, letter-spacing 2)
  - Optional onTitleTap for tappable titles
- Update all screens to use the new helper, removing redundant overrides
- Remove terminal icon from status_screen title, use plain centered text
- Change appBarTheme centerTitle to false (left-aligned)
- Remove bottom dividers from all screens

lib/status_screen.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
+import 'app_bar.dart';
 import 'bridge/location_bridge.dart';
 
 class StatusScreen extends StatefulWidget {
@@ -179,33 +180,8 @@ class _StatusScreenState extends State<StatusScreen> {
   Widget build(BuildContext context) {
     return Scaffold(
       backgroundColor: const Color(0xFF0d0d0d),
-      appBar: AppBar(
-        backgroundColor: const Color(0xFF161616),
-        elevation: 0,
-        title: Row(
-          children: [
-            const Icon(Icons.terminal, color: Color(0xFF00bcd4), size: 18),
-            const SizedBox(width: 10),
-            const Text(
-              'EVENT LOG',
-              style: TextStyle(
-                fontFamily: 'monospace',
-                fontSize: 14,
-                fontWeight: FontWeight.w700,
-                letterSpacing: 2,
-                color: Color(0xFFe0e0e0),
-              ),
-            ),
-          ],
-        ),
-        leading: IconButton(
-          icon: const Icon(
-            Icons.arrow_back,
-            color: Color(0xFF9e9e9e),
-            size: 20,
-          ),
-          onPressed: () => Navigator.pop(context),
-        ),
+      appBar: buildTracPulseAppBar(
+        title: 'EVENT LOG',
         actions: [
           IconButton(
             icon: const Icon(
@@ -220,10 +196,6 @@ class _StatusScreenState extends State<StatusScreen> {
             onPressed: _loadLogs,
           ),
         ],
-        bottom: PreferredSize(
-          preferredSize: const Size.fromHeight(1),
-          child: Container(height: 1, color: const Color(0xFF2a2a2a)),
-        ),
       ),
       body: Column(
         children: [