feature/go-rewrite : base Go avec walk GUI

- Rewrite complet en Go : exe unique sans _internal/, sans extraction temp
- GUI Windows-native via github.com/lxn/walk (TableView, TextEdit, PushButton)
- Meme fonctionnalites : check repos, pull, checkout, auto-update, logs
- build.bat : go build -ldflags "-H windowsgui -s -w" -> 9.6 Mo, zero dependance

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

_internal/_tcl_data/msgs/pl.msg

@@ -1,52 +0,0 @@
-# created by tools/loadICU.tcl -- do not edit
-namespace eval ::tcl::clock {
-    ::msgcat::mcset pl DAYS_OF_WEEK_ABBREV [list \
-        "N"\
-        "Pn"\
-        "Wt"\
-        "\u015ar"\
-        "Cz"\
-        "Pt"\
-        "So"]
-    ::msgcat::mcset pl DAYS_OF_WEEK_FULL [list \
-        "niedziela"\
-        "poniedzia\u0142ek"\
-        "wtorek"\
-        "\u015broda"\
-        "czwartek"\
-        "pi\u0105tek"\
-        "sobota"]
-    ::msgcat::mcset pl MONTHS_ABBREV [list \
-        "sty"\
-        "lut"\
-        "mar"\
-        "kwi"\
-        "maj"\
-        "cze"\
-        "lip"\
-        "sie"\
-        "wrz"\
-        "pa\u017a"\
-        "lis"\
-        "gru"\
-        ""]
-    ::msgcat::mcset pl MONTHS_FULL [list \
-        "stycze\u0144"\
-        "luty"\
-        "marzec"\
-        "kwiecie\u0144"\
-        "maj"\
-        "czerwiec"\
-        "lipiec"\
-        "sierpie\u0144"\
-        "wrzesie\u0144"\
-        "pa\u017adziernik"\
-        "listopad"\
-        "grudzie\u0144"\
-        ""]
-    ::msgcat::mcset pl BCE "p.n.e."
-    ::msgcat::mcset pl CE "n.e."
-    ::msgcat::mcset pl DATE_FORMAT "%Y-%m-%d"
-    ::msgcat::mcset pl TIME_FORMAT "%H:%M:%S"
-    ::msgcat::mcset pl DATE_TIME_FORMAT "%Y-%m-%d %H:%M:%S %z"
-}