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

run_tb.sh

@@ -0,0 +1,82 @@
+#!/bin/bash
+# run_tb.sh - Run Vivado XSIM testbench for a module
+#
+# Usage: ./run_tb.sh <module>
+#        ./run_tb.sh mod_add
+#        ./run_tb.sh --list
+#
+# Prerequisites:
+#   Vivado 2019.2 at /opt/Xilinx/Vivado/2019.2/
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+VIVADO_SETTINGS="/opt/Xilinx/Vivado/2019.2/settings64.sh"
+
+if [ "$1" = "--list" ]; then
+    echo "Available modules:"
+    for d in "$SCRIPT_DIR"/sync_rtl/*/TB; do
+        if [ -f "$d/xsim_run.tcl" ]; then
+            name=$(basename "$(dirname "$d")")
+            echo "  $name"
+        fi
+    done
+    exit 0
+fi
+
+if [ -z "$1" ]; then
+    echo "Usage: $0 <module_name>"
+    echo "       $0 --list"
+    exit 1
+fi
+
+MODULE="$1"
+TB_DIR="$SCRIPT_DIR/sync_rtl/$MODULE/TB"
+TCL_FILE="$TB_DIR/xsim_run.tcl"
+
+if [ ! -f "$TCL_FILE" ]; then
+    echo "ERROR: No xsim_run.tcl found for module '$MODULE'"
+    echo "       Expected: $TCL_FILE"
+    echo "       Run '$0 --list' to see available modules"
+    exit 1
+fi
+
+# Source Vivado environment
+if [ -f "$VIVADO_SETTINGS" ]; then
+    source "$VIVADO_SETTINGS"
+else
+    echo "ERROR: Vivado settings not found at $VIVADO_SETTINGS"
+    exit 1
+fi
+
+# Fix ncurses compatibility for Vivado 2019.2 on modern Linux
+export LD_PRELOAD="${LD_PRELOAD}${LD_PRELOAD:+:}/usr/lib64/libtinfo.so.5"
+
+cd "$SCRIPT_DIR"
+echo "========================================"
+echo " Running testbench for: $MODULE"
+echo "========================================"
+
+# Run xvlog + xelab + xsim commands directly (not via vivado batch)
+# Extract and execute xvlog, xelab, xsim lines from the TCL
+grep -E '^xvlog ' "$TCL_FILE" | while read -r cmd; do
+    if [[ "$cmd" != \#* ]]; then
+        echo "  $cmd"
+        eval "$cmd" 2>&1 | grep -E "ERROR|WARNING|analyzing|Compiling|Built" || true
+    fi
+done
+
+grep -E '^xelab ' "$TCL_FILE" | while read -r cmd; do
+    if [[ "$cmd" != \#* ]]; then
+        echo "  $cmd"
+        eval "$cmd" 2>&1 | grep -E "ERROR|WARNING|Compiling|Built" || true
+    fi
+done
+
+echo ""
+echo "--- Running simulation ---"
+grep -E '^xsim ' "$TCL_FILE" | while read -r cmd; do
+    if [[ "$cmd" != \#* ]]; then
+        eval "$cmd" 2>&1
+    fi
+done