- refactor timeline component with iframe-based time travel system

- implement auto-scrolling when dragging near viewport edges
- add exit button for time travel mode
- increase timeline height from 50px to 70px
- replace direct DOM manipulation with isolated iframe content
- add loading and error indicators for time travel operations
- intercept internal links to maintain historical navigation
- fix slider thumb position calculation during scrolling
- change title for timeline toggle to make it sound more exciting

Author: TobiasMue91

timeline.html

@@ -9,7 +9,7 @@
     }
 
     #timeline-container.collapsed {
-        bottom: -50px;
+        bottom: -70px;
     }
 
     #timeline-toggle {
@@ -44,7 +44,7 @@
         display: flex;
         align-items: center;
         overflow-x: auto;
-        height: 50px;
+        height: 70px;
         padding: 10px 10px 10px 30px;
         color: #fff;
     }
@@ -106,7 +106,7 @@
     }
 </style>
 <div id="timeline-container" class="collapsed">
-    <div id="timeline-toggle" title="Toggle timeline feature">∧</div>
+    <div id="timeline-toggle" title="Open Time Travel">∧</div>
     <div id="timeline">
         <div id="slider">
             <div class="slider-track"></div>