Move templates and assets to templates/ folder

- Move all HTML templates to templates/
- Move Platinum assets to templates/Platinum/
- Update default paths in generate_report.py

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

templates/Platinum/Others/bg-tiled.xpm

@@ -0,0 +1,15 @@
+/* XPM */
+static char * bg_tiled_xpm[] = {
+"8 8 4 1",
+" 	c None",
+".	c #DDDDDD",
+"+	c #CCCCCC",
+"@	c #EEEEEE",
+".+++++++",
+"+.@+++@+",
+"++.+++++",
+"@+++@+++",
+"++++++.+",
+"++@++.@+",
+"++++.+++",
+"@+++@+++"};