feat(cleaner): add directory for video name cleaning with CLI tool and registry entry

cleaner/go.mod

@@ -0,0 +1,3 @@
+module tcleaner
+
+go 1.23.6

cleaner/install_grader_context_menu.reg

@@ -0,0 +1,7 @@
+Windows Registry Editor Version 5.00
+
+[HKEY_CURRENT_USER\Software\Classes\*\shell\Clean video name]
+@="Clean video name"
+
+[HKEY_CURRENT_USER\Software\Classes\*\shell\Clean video name\command]
+@="C:\\Users\\administrator\\go\\bin\\tcleaner.exe \"%1\"" 

cleaner/main.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+)
+
+func main() {
+	flag.Parse()
+	if flag.NArg() == 0 {
+		fmt.Println("Usage: cleaner <files>")
+		os.Exit(1)
+	}
+	// regex to match " - 2025-07-08 01h31m45s - "
+	re := regexp.MustCompile(` - (\d{4}-\d{2}-\d{2} \d{2}h\d{2}m\d{2}s) - `)
+
+	for _, file := range flag.Args() {
+		info, err := os.Stat(file)
+		if err != nil {
+			fmt.Printf("ERROR: %v\n", err)
+			continue
+		}
+		if info.IsDir() {
+			fmt.Printf("SKIP (directory): %s\n", file)
+			continue
+		}
+		name := filepath.Base(file)
+		match := re.FindStringSubmatch(name)
+		if match == nil {
+			fmt.Printf("SKIP (no date pattern): %s\n", name)
+			continue
+		}
+
+		newName := match[1] + filepath.Ext(name)
+		if name == newName {
+			fmt.Printf("SKIP (already named): %s\n", name)
+			continue
+		}
+
+		if _, err := os.Stat(newName); err == nil {
+			fmt.Printf("SKIP (target exists): %s -> %s\n", name, newName)
+			continue
+		}
+
+		err = os.Rename(name, newName)
+		if err != nil {
+			fmt.Printf("ERROR renaming %s: %v\n", name, err)
+		} else {
+			fmt.Printf("RENAMED: %s -> %s\n", name, newName)
+		}
+		continue
+	}
+}