feat: init mlkem project with Verilator test framework

- sync_rtl/common/: skid_buffer, pipeline_reg, defines (valid/ready)
- sync_rtl/mod_add/: modular adder example with Verilator C++ TB
- test_framework/: Python-driven Verilator compile/sim/compare pipeline
- test_framework/modules/mod_add/: 50-vector test plan, full鏈路 PASS
- .trellis/spec/: RTL and test_framework conventions documented

obj_dir/Vmod_add_sync_classes.mk

@@ -0,0 +1,51 @@
+# Verilated -*- Makefile -*-
+# DESCRIPTION: Verilator output: Make include file with class lists
+#
+# This file lists generated Verilated files, for including in higher level makefiles.
+# See Vmod_add_sync.mk for the caller.
+
+### Switches...
+# C11 constructs required?  0/1 (always on now)
+VM_C11 = 1
+# Timing enabled?  0/1
+VM_TIMING = 0
+# Coverage output mode?  0/1 (from --coverage)
+VM_COVERAGE = 0
+# Parallel builds?  0/1 (from --output-split)
+VM_PARALLEL_BUILDS = 0
+# Tracing output mode?  0/1 (from --trace-fst/--trace-saif/--trace-vcd)
+VM_TRACE = 0
+# Tracing output mode in FST format?  0/1 (from --trace-fst)
+VM_TRACE_FST = 0
+# Tracing output mode in SAIF format?  0/1 (from --trace-saif)
+VM_TRACE_SAIF = 0
+# Tracing output mode in VCD format?  0/1 (from --trace-vcd)
+VM_TRACE_VCD = 0
+
+### Object file lists...
+# Generated module classes, fast-path, compile with highest optimization
+VM_CLASSES_FAST += \
+  Vmod_add_sync \
+  Vmod_add_sync___024root__0 \
+
+# Generated module classes, non-fast-path, compile with low/medium optimization
+VM_CLASSES_SLOW += \
+  Vmod_add_sync___024root__Slow \
+  Vmod_add_sync___024root__0__Slow \
+
+# Generated support classes, fast-path, compile with highest optimization
+VM_SUPPORT_FAST += \
+
+# Generated support classes, non-fast-path, compile with low/medium optimization
+VM_SUPPORT_SLOW += \
+  Vmod_add_sync__Syms__Slow \
+
+# Global classes, need linked once per executable, fast-path, compile with highest optimization
+VM_GLOBAL_FAST += \
+  verilated \
+  verilated_threads \
+
+# Global classes, need linked once per executable, non-fast-path, compile with low/medium optimization
+VM_GLOBAL_SLOW += \
+
+# Verilated -*- Makefile -*-