feat: Implement settings panel for vertical and horizontal lines

- Add default settings (color, width, style, opacity) for horizontal_line and vertical_line
- Enable settings panel to open on double-click for horizontal/vertical lines
- Update rendering to support full styling (color, width, style, opacity) with visual selection handles
- Show/hide Text tab based on drawing type (trend_line/ray/rectangle only)
- Add proper drag handling to move entire horizontal/vertical lines

index.html

@@ -151,7 +151,7 @@
                         <!-- Tabs -->
                         <div class="flex border-b border-[#2d3a4f] mb-4">
                             <button class="flex-1 py-2 text-center text-blue-500 border-b-2 border-blue-500 font-medium" id="tlTabStyle" onclick="window.switchTLTab('style')">Style</button>
-                            <button class="flex-1 py-2 text-center text-gray-400 hover:text-white" id="tlTabText" onclick="window.switchTLTab('text')">Text</button>
+                            <button class="flex-1 py-2 text-center text-gray-400 hover:text-white" id="tlTabText" onclick="window.switchTLTab('text')" style="display: none;">Text</button>
                         </div>
 
                         <!-- Style Tab Content -->