Fix Magic DNS issue: Enable DNS acceptance in Linux installation script

Changed --accept-dns=false to --accept-dns=true in quick-install.sh:
- Automatic registration command (line 347)
- Manual registration example command (line 357)

This ensures Linux clients also receive Headscale Magic DNS configuration
(100.64.0.1) automatically during installation, enabling proper name resolution
for *.headscale.local domains on all platforms.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

quick-install.sh

@@ -344,7 +344,7 @@ register_headscale() {
         --login-server="$HEADSCALE_SERVER" \
         --authkey="$PREAUTH_KEY" \
         --accept-routes \
-        --accept-dns=false >/dev/null 2>&1; then
+        --accept-dns=true >/dev/null 2>&1; then
         
         print_success "Headscale 등록 성공!"
         
@@ -354,7 +354,7 @@ register_headscale() {
         # 수동 등록 모드
         print_info "다음 명령을 실행하여 수동 등록하세요:"
         echo ""
-        echo "tailscale up --login-server=\"$HEADSCALE_SERVER\" --authkey=\"$PREAUTH_KEY\""
+        echo "tailscale up --login-server=\"$HEADSCALE_SERVER\" --authkey=\"$PREAUTH_KEY\" --accept-routes --accept-dns=true"
         echo ""
         
         # 등록 URL 시도