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>

git.go

@@ -0,0 +1,134 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+type RepoResult struct {
+	Name         string
+	Path         string
+	URL          string
+	Pending      bool
+	UpToDate     bool
+	Offline      bool
+	NeedsClone   bool
+	Error        string
+	NewCommits   int
+	LocalChanges int
+}
+
+func runGit(args []string, cwd string, timeout time.Duration) (code int, stdout string, stderr string) {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	fullArgs := append([]string{"-c", "safe.directory=*"}, args...)
+	cmd := newGitCmd(ctx, fullArgs, cwd)
+
+	var outBuf, errBuf strings.Builder
+	cmd.Stdout = &outBuf
+	cmd.Stderr = &errBuf
+
+	err := cmd.Run()
+	stdout = strings.TrimSpace(outBuf.String())
+	stderr = strings.TrimSpace(errBuf.String())
+
+	if err != nil {
+		if ctx.Err() == context.DeadlineExceeded {
+			return 1, stdout, "Timeout"
+		}
+		var exitErr *exec.ExitError
+		if errors.As(err, &exitErr) {
+			return exitErr.ExitCode(), stdout, stderr
+		}
+		return -1, stdout, err.Error()
+	}
+	return 0, stdout, stderr
+}
+
+func absRepoPath(rel string) string {
+	if filepath.IsAbs(rel) {
+		return rel
+	}
+	return filepath.Join(exeDir(), rel)
+}
+
+func checkRepo(cfg RepoConfig) RepoResult {
+	res := RepoResult{Name: cfg.Name, URL: cfg.URL}
+	local := absRepoPath(cfg.Path)
+	res.Path = local
+
+	if _, err := os.Stat(filepath.Join(local, ".git")); os.IsNotExist(err) {
+		res.NeedsClone = true
+		return res
+	}
+
+	runGit([]string{"remote", "set-url", "origin", cfg.URL}, local, 10*time.Second)
+
+	code, _, stderr := runGit([]string{"fetch", "origin"}, local, 60*time.Second)
+	if code != 0 {
+		for _, kw := range []string{"could not resolve", "connection refused", "unable to connect", "timed out", "the remote end hung up"} {
+			if strings.Contains(strings.ToLower(stderr), kw) {
+				res.Offline = true
+				res.Error = "Hors ligne"
+				return res
+			}
+		}
+		res.Error = "Fetch: " + stderr
+		return res
+	}
+
+	_, branch, _ := runGit([]string{"rev-parse", "--abbrev-ref", "HEAD"}, local, 5*time.Second)
+	if branch == "" {
+		branch = "master"
+	}
+
+	_, countStr, _ := runGit([]string{"rev-list", "--count", "HEAD..origin/" + branch}, local, 5*time.Second)
+	fmt.Sscanf(countStr, "%d", &res.NewCommits)
+
+	_, status, _ := runGit([]string{"status", "--porcelain"}, local, 5*time.Second)
+	if status != "" {
+		res.LocalChanges = len(strings.Split(strings.TrimSpace(status), "\n"))
+	}
+
+	res.UpToDate = res.NewCommits == 0 && res.LocalChanges == 0
+	return res
+}
+
+func doClone(cfg RepoConfig) error {
+	local := absRepoPath(cfg.Path)
+	if err := os.MkdirAll(filepath.Dir(local), 0755); err != nil {
+		return err
+	}
+	code, _, stderr := runGit([]string{"clone", cfg.URL, local}, "", 300*time.Second)
+	if code != 0 {
+		return fmt.Errorf("%s", stderr)
+	}
+	return nil
+}
+
+func doPull(res RepoResult) error {
+	_, branch, _ := runGit([]string{"rev-parse", "--abbrev-ref", "HEAD"}, res.Path, 5*time.Second)
+	if branch == "" {
+		branch = "master"
+	}
+	code, _, stderr := runGit([]string{"pull", "origin", branch}, res.Path, 120*time.Second)
+	if code != 0 {
+		return fmt.Errorf("%s", stderr)
+	}
+	return nil
+}
+
+func doCheckout(res RepoResult) error {
+	code, _, stderr := runGit([]string{"checkout", "--", "."}, res.Path, 30*time.Second)
+	if code != 0 {
+		return fmt.Errorf("%s", stderr)
+	}
+	return nil
+}