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>

.gitignore

@@ -0,0 +1,71 @@
+# ============================================================================
+# retroDE_ps2 root .gitignore
+# POLICY: copyrighted PS2 content (BIOS, game code, GS dumps, and ANYTHING
+# derived from a dump) is LOCAL ONLY and must NEVER be committed.
+# See captures/gs/.gitignore for the whitelist policy. When in doubt, ignore it.
+# NOTE: git has NO inline comments — every comment is on its own line.
+# ============================================================================
+
+# ---- copyrighted / dump-derived content (NEVER commit) ----
+/captures/
+*.elf
+*.trace
+*bios*.hex
+*bios*.bin
+*bios*.rom
+*real_tex*.mem
+*real_draw*.hex
+image.hex
+manifest.hex
+# dump-derived SH3 fixtures — DATA ONLY (.mem/.vh/.hex/.dat). The SH3 .sv test-
+# benches, .py fixture generators, and .c uploader are the project's OWN code and
+# ARE kept; only the extracted game data is local-only.
+*sh3*.mem
+*sh3*.vh
+*sh3*.hex
+*sh3*.dat
+sh3_*.mem
+
+# ---- python cache ----
+__pycache__/
+*.pyc
+
+# ---- build / tool output (regenerable) ----
+/sim/build/
+/sim/traces/
+/synth/**/output_files/
+/synth/**/qsys/
+/synth/**/db/
+/synth/**/incremental_db/
+/synth/**/dni/
+/synth/**/qdb/
+/synth/**/.qsys_edit/
+/synth/de25_nano/top_psmct32_raster_demo/baseline_*/
+/synth/de25_nano/experiments/
+*.sof
+*.pof
+*.rbf
+*.ddm
+*.cdb
+*.hdb
+*.qws
+*.jdi
+*.smsg
+
+# ---- vendored upstream emulators (large; available from upstream) ----
+/third_party/PCSX2/
+/third_party/DobieStation/
+
+# ---- screenshots / framebuffer captures (may show copyrighted game frames; large) ----
+/Screenshots/
+
+# ---- synthetic bulk vectors + compiled golden-runner binaries (regenerable) ----
+/sim/vectors/bios/nop_sled.bin
+/sim/golden/dobiestation_runner/smoke_test
+/sim/golden/dobiestation_runner/trace_runner
+/tools/ps2_feeder
+
+# ---- editor / OS noise ----
+*.swp
+*~
+.DS_Store