feat: CI/CD, Bash-Completion und README-Verbesserungen

- GitHub Actions CI Pipeline (Tests, Clippy, Format-Checks)
- GitHub Actions Release Pipeline (Multi-Platform Builds)
- Bash-Completion Script für Shell-Autovervollständigung
- Zsh-Completion Script (_ntu)
- README Badges (CI, Release, Version, License)
- Installationsanleitung für Pre-built Binaries
- Alte build.yaml entfernt (ersetzt durch moderne ci.yml)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

completions/ntu.bash

@@ -0,0 +1,35 @@
+# Bash completion for ntu (NameToUnix)
+
+_ntu_completion() {
+    local cur prev opts
+    COMPREPLY=()
+    cur="${COMP_WORDS[COMP_CWORD]}"
+    prev="${COMP_WORDS[COMP_CWORD-1]}"
+
+    # All available options
+    opts="--dry-run --no-changes --quiet --force --exclude --verbose --modify-root --special --help --version -n -q -f -e -v -h -V"
+
+    # Handle options that require arguments
+    case "${prev}" in
+        -e|--exclude)
+            # Suggest glob patterns
+            COMPREPLY=( $(compgen -W '"*.tmp" "*.log" "*.bak" "*.swp" "*~"' -- ${cur}) )
+            return 0
+            ;;
+        *)
+            ;;
+    esac
+
+    # If current word starts with -, complete with options
+    if [[ ${cur} == -* ]] ; then
+        COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+        return 0
+    fi
+
+    # Otherwise complete with directories and files
+    COMPREPLY=( $(compgen -f -- ${cur}) )
+    return 0
+}
+
+# Register completion function
+complete -F _ntu_completion ntu