v0.7.6 - Clone dossier non-vide et verification rapide

Changements :
- Clone dans dossier non-vide (git init + remote add + fetch + checkout)
- Verification rapide via git ls-remote au lieu de git fetch (timeout 15s)
- Support branche par repo dans config.ini (champ branch)
- Suppression fichiers Python et artefacts PyInstaller (_internal/)

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

config.go

@@ -8,9 +8,10 @@ import (
 )
 
 type RepoConfig struct {
-	Name string
-	URL  string
-	Path string
+	Name   string
+	URL    string
+	Path   string
+	Branch string // branche à suivre (défaut: "master")
 }
 
 type SelfUpdateConfig struct {
@@ -37,10 +38,15 @@ func loadConfig() ([]RepoConfig, SelfUpdateConfig, error) {
 		case strings.HasPrefix(section, "repo:"):
 			name := strings.TrimPrefix(section, "repo:")
 			if kv["url"] != "" && kv["path"] != "" {
+				branch := kv["branch"]
+				if branch == "" {
+					branch = "master"
+				}
 				repos = append(repos, RepoConfig{
-					Name: name,
-					URL:  kv["url"],
-					Path: kv["path"],
+					Name:   name,
+					URL:    kv["url"],
+					Path:   kv["path"],
+					Branch: branch,
 				})
 			}
 		case section == "self-update":