fix(tb): fix Vivado 2019.2 compatibility and add run_tb.sh

- Replace -include_dirs . with -i . (Vivado 2019.2 syntax)
- Add --timescale 1ns/1ps to all xelab commands
- Add LD_PRELOAD comment for ncurses compatibility
- Add run_tb.sh convenience script
  Usage: ./run_tb.sh mod_add
         ./run_tb.sh --list
- Update spec with Vivado 2019.2 compatibility notes

sync_rtl/sample_ntt/TB/xsim_run.tcl

@@ -1,3 +1,7 @@
+# NOTE: On some systems, you may need:
+#   export LD_PRELOAD=/usr/lib64/libtinfo.so.5
+# before running this script.
+
 # xsim_run.tcl - Vivado xsim compilation and simulation for sample_ntt_sync
 #
 # Compiles sample_ntt_sync RTL + SHA3 dependencies + testbench and runs simulation.
@@ -26,13 +30,13 @@ set TB_DIR       sync_rtl/sample_ntt/TB
 puts "=== Compiling RTL sources ==="
 
 # Keccak round (combinational, used by keccak_core)
-xvlog -sv -include_dirs . ${SHA3_DIR}/keccak_round.v
+xvlog -sv -i . ${SHA3_DIR}/keccak_round.v
 
 # Keccak core (24-round sequential core, used by sample_ntt_sync)
-xvlog -sv -include_dirs . ${SHA3_DIR}/keccak_core.v
+xvlog -sv -i . ${SHA3_DIR}/keccak_core.v
 
 # sample_ntt_sync (DUT) — uses `include "sync_rtl/common/defines.vh"
-xvlog -sv -include_dirs . ${SRC_DIR}/sample_ntt_sync.v
+xvlog -sv -i . ${SRC_DIR}/sample_ntt_sync.v
 
 # ================================================================
 # Step 2: Compile testbench
@@ -44,7 +48,7 @@ xvlog -sv ${TB_DIR}/tb_sample_ntt_xsim.v
 # Step 3: Elaborate snapshot (xelab)
 # ================================================================
 puts "=== Elaborating snapshot ==="
-xelab tb_sample_ntt_xsim -s tb_sample_ntt_xsim
+xelab tb_sample_ntt_xsim -s tb_sample_ntt_xsim --timescale 1ns/1ps
 
 # ================================================================
 # Step 4: Run simulation