v0.6.4 - Retour onedir (configuration stable)

Changements :
- Retour a --onedir : seule configuration sans erreur DLL confirmee
- _internal/ recommite dans le repo
- build.bat restaure avec copie automatique de _internal/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

_internal/_tcl_data/msgs/zh_sg.msg

@@ -0,0 +1,8 @@
+# created by tools/loadICU.tcl -- do not edit
+namespace eval ::tcl::clock {
+    ::msgcat::mcset zh_SG AM "\u4e0a\u5348"
+    ::msgcat::mcset zh_SG PM "\u4e2d\u5348"
+    ::msgcat::mcset zh_SG DATE_FORMAT "%d %B %Y"
+    ::msgcat::mcset zh_SG TIME_FORMAT_12 "%P %I:%M:%S"
+    ::msgcat::mcset zh_SG DATE_TIME_FORMAT "%d %B %Y %P %I:%M:%S %z"
+}