✨ feat: smart Xilinx version scanning — pick newest, log all versions

_version discovery:
- _scan_xilinx_root() collects ALL versions under Vitis/*/bin/ and Vivado/*/bin/
- _parse_version_tuple() semantic version comparison (2023.2 > 2018.3)
- Defaults to newest version, Vitis preferred over Vivado for same version
- _find_executable() search order: PATH → legacy vitis_path → scan xilinx_root → common paths

_version reporting:
- _get_tool_version(): tries -version flag first, falls back to path parsing
- _version_from_path(): extracts version from install path (e.g., .../Vitis/2023.2/bin/xsct → 2023.2)
- Step 1 logs each tool with version: ✓ xsct: /path [v2023.2]
- If multiple versions found, lists all: xsct versions found: 2023.2 (Vitis), 2018.3 (Vivado)

Cross-platform:
- Handles Windows path separators via Path()
- Expanded common Windows install paths

src/gui/main_window.py

@@ -767,19 +767,33 @@ class MainWindow(ctk.CTk):
 
         # Check Vitis/Vivado tools
         self._log_message("  Checking Vitis/Vivado tools...")
+        if self._config.xilinx_path:
+            self._log_message(f"  Xilinx root: {self._config.xilinx_path}")
         result = check_vitis(self._config)
         status_dict = get_tool_status_dict(result)
 
         for tool_name, tool_info in status_dict["tools"].items():
             if tool_info["found"]:
+                ver_info = f" [v{tool_info['version']}]" if tool_info.get("version") else ""
                 alias_note = f" (via {tool_info['alias']})" if tool_info.get("alias") and tool_info["alias"] != tool_name else ""
-                self._log_message(f"    ✓ {tool_name}: {tool_info['path']}{alias_note}")
+                self._log_message(f"    ✓ {tool_name}: {tool_info['path']}{ver_info}{alias_note}")
             else:
                 self._log_message(f"    ✗ {tool_name}: {tool_info['error']}")
 
         if result.is_ready:
             self._vitis_status.configure(text="Vitis: Ready", text_color=SUCCESS_COLOR)
             self._log_message("  Vitis/Vivado tools available")
+            # Report all found versions for diagnostics
+            if self._config.xilinx_path:
+                try:
+                    from vitis_checker import get_all_found_versions
+                    for t in ("xsct", "program_flash", "bootgen"):
+                        vers = get_all_found_versions(self._config.xilinx_path, t)
+                        if len(vers) > 1:
+                            ver_list = ", ".join(f"{v} ({p})" for v, p in vers)
+                            self._log_message(f"    {t} versions found: {ver_list}")
+                except Exception:
+                    pass
         else:
             self._vitis_status.configure(text="Vitis: Partial", text_color=WARNING_COLOR)
             self._log_message(f"  Issues: {'; '.join(result.errors)}")