Initial commit: retroDE_ps2 — first-of-its-kind PS2 GS FPGA core (DE25-Nano / Agilex 5)

RTL (GS rasterizer, EE core stub, platform bridge, LPDDR4B path), sim regression
(272 TBs), docs, and tooling. Copyrighted PS2 content (BIOS, game code, GS dumps,
and all dump-derived textures/traces) is excluded via .gitignore and stays local.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

qsys/qsys_top/sim/xcelium/cds_libs/simulator.cds.lib

@@ -0,0 +1,10 @@
+
+DEFINE std            $CDS_ROOT/tools/inca/files/STD/           
+DEFINE synopsys       $CDS_ROOT/tools/inca/files/SYNOPSYS/      
+DEFINE ieee           $CDS_ROOT/tools/inca/files/IEEE/          
+DEFINE ambit          $CDS_ROOT/tools/inca/files/AMBIT/         
+DEFINE vital_memory   $CDS_ROOT/tools/inca/files/VITAL_MEMORY/  
+DEFINE ncutils        $CDS_ROOT/tools/inca/files/NCUTILS/       
+DEFINE ncinternal     $CDS_ROOT/tools/inca/files/NCINTERNAL/    
+DEFINE ncmodels       $CDS_ROOT/tools/inca/files/NCMODELS/      
+DEFINE cds_assertions $CDS_ROOT/tools/inca/files/CDS_ASSERTIONS/