feat: Complete 3D radar enhancements with labels, interactions, and trails

Implements comprehensive 3D radar view enhancements:

- Fixed map tile alignment using proper Web Mercator projection calculations
- Added dynamic aircraft labels showing callsign, altitude, and speed
- Implemented click interactions with raycasting for aircraft selection
- Created flight trail visualization with toggle functionality
- Enhanced visual feedback with selection highlighting
- Improved tile positioning with precise geographic calculations

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

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

assets/static/index.html

@@ -413,6 +413,7 @@
                 <div class="radar3d-controls">
                     <button id="radar3d-reset" disabled>Reset View</button>
                     <button id="radar3d-auto-rotate" disabled>Auto Rotate</button>
+                    <button id="radar3d-trails" disabled>Show Trails</button>
                     <label>
                         <input type="range" id="radar3d-range" min="10" max="500" value="100" disabled>
                         Range: <span id="radar3d-range-value">100</span> km