Balance footer columns: Move literature reference to left side

- Move "Formeln aus:" section from right column to left column
- Place it after footnote 4 with horizontal separator
- This balances the text distribution between both footer columns
- Right column now only contains the deviations section

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

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

Author: Peuqui

src/components/Footer.vue

@@ -96,8 +96,9 @@
             <sup>4)</sup>
             {{ $t("sub4") }} (EV)
           </div>
-        </div>
-        <div class="col-3">
+          
+          <hr />
+          
           <div>
             {{ $t("colRight1") }}
             <br />M.Rehm · N.Hulde · T.Kammerer · A.S.Meidert · K.Hofmann-Kiefer
@@ -116,9 +117,8 @@
               >
             </nav>
           </div>
-
-          <hr />
-
+        </div>
+        <div class="col-3">
           <div v-html="$t('colRight2')"></div>
         </div>
       </div>