refactor: make git package handle all git operations (#38543)

before: gitrepo vs git packages
after: git package fully handle all git operations

by the way, use `WithRepo(repo)` instead of `WithDir(repo.Path)` to hide
path details.

benefits:

1. remove all unnecessary wrappers, developers no need to struggle with
"which package should be used"
2. simplify code, RepositoryFacade can (will) be used everywhere, all
"path" details are (will be) hidden

modules/git/remote_managed.go

@@ -0,0 +1,57 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package git
+
+import (
+	"context"
+	"errors"
+
+	"gitea.dev/modules/git/gitcmd"
+	giturl "gitea.dev/modules/git/url"
+	"gitea.dev/modules/util"
+)
+
+type RemoteOption string
+
+const (
+	RemoteOptionMirrorPush  RemoteOption = "--mirror=push"
+	RemoteOptionMirrorFetch RemoteOption = "--mirror=fetch"
+)
+
+func ManagedRemoteAdd(ctx context.Context, repo RepositoryFacade, remoteName, remoteURL string, options ...RemoteOption) error {
+	return LockConfigAndDo(ctx, repo, func(ctx context.Context) error {
+		cmd := gitcmd.NewCommand("remote", "add")
+		if len(options) > 0 {
+			switch options[0] {
+			case RemoteOptionMirrorPush:
+				cmd.AddArguments("--mirror=push")
+			case RemoteOptionMirrorFetch:
+				cmd.AddArguments("--mirror=fetch")
+			default:
+				return errors.New("unknown remote option: " + string(options[0]))
+			}
+		}
+		_, _, err := cmd.AddDynamicArguments(remoteName, remoteURL).WithRepo(repo).RunStdString(ctx)
+		return err
+	})
+}
+
+func ManagedRemoteRemove(ctx context.Context, repo RepositoryFacade, remoteName string) error {
+	return LockConfigAndDo(ctx, repo, func(ctx context.Context) error {
+		cmd := gitcmd.NewCommand("remote", "rm").AddDynamicArguments(remoteName)
+		_, _, err := cmd.WithRepo(repo).RunStdString(ctx)
+		return err
+	})
+}
+
+func ParseRemoteAddressURL(ctx context.Context, repo RepositoryFacade, remoteName string) (*giturl.GitURL, error) {
+	addr, err := GetRemoteAddress(ctx, repo, remoteName)
+	if err != nil {
+		return nil, err
+	}
+	if addr == "" {
+		return nil, util.NewNotExistErrorf("remote '%s' does not exist", remoteName)
+	}
+	return giturl.ParseGitURL(addr)
+}