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/ip/qsys_top/rst_in/rst_in.cmp

@@ -0,0 +1,7 @@
+	component rst_in is
+		port (
+			in_reset_n  : in  std_logic := 'X'; -- reset_n
+			out_reset_n : out std_logic         -- reset_n
+		);
+	end component rst_in;
+