#1651 bug: ResolveAbsPath incorrectly expands relative paths starting with ~ (e.g. ~backup)

Describe the bug

ResolveAbsPath in src/pkg/utils/file_utils.go expands any path where strings.HasPrefix(path, "~") is true by replacing ~ with xdg.Home.

This causes relative directory and file names that happen to start with a tilde (such as ~backup, ~temp, ~notes.txt, or Office lock files like ~$document.docx) to be concatenated directly to the home directory string (e.g. /home/userbackup or C:\Users\\\userbackup), rather than being resolved relative to the current working directory.

To Reproduce

In any directory, create a folder starting with ~:
```
mkdir ~test
```
Try to launch superfile pointing to that directory:
```
spf ~test
```
Superfile fails to open ./~test and falls back to $HOME because it attempts to stat /home/<user>test (or C:\Users\<user>test).
Inside superfile, open the prompt (: or >) and run:
```
cd ~test
```
An error is shown: /home/<user>test: no such file or directory.

Expected behavior

Tilde expansion should only trigger if the argument is exactly "~", starts with "~/", or starts with "~\\" (on Windows). Other paths starting with ~ should be treated as relative paths and resolved against currentDir.

Code Reference

In src/pkg/utils/file_utils.go (lines 206-210):

func ResolveAbsPath(currentDir string, path string) string {
	if !filepath.IsAbs(currentDir) {
		slog.Warn("currentDir is not absolute", "currentDir", currentDir)
	}
	if strings.HasPrefix(path, "~") {
		// Current: unconditionally replaces '~' anywhere it starts the string
		path = strings.Replace(path, "~", xdg.Home, 1)
	}
	if !filepath.IsAbs(path) {
		path = filepath.Join(currentDir, path)
	}
	return filepath.Clean(path)
}

Proposed fix

func ResolveAbsPath(currentDir string, path string) string {
	if !filepath.IsAbs(currentDir) {
		slog.Warn("currentDir is not absolute", "currentDir", currentDir)
	}
	if path == "~" {
		path = xdg.Home
	} else if strings.HasPrefix(path, "~/") || (runtime.GOOS == "windows" && strings.HasPrefix(path, "~\\")) {
		path = filepath.Join(xdg.Home, path[2:])
	}
	if !filepath.IsAbs(path) {
		path = filepath.Join(currentDir, path)
	}
	return filepath.Clean(path)
}

System information

OS: All platforms (Linux, macOS, Windows)
superfile version: v1.6.0 / main (commit b2af9a6)