fix: update CI/CD to run bruno tests from collection root

Bruno CLI requires running from the collection root directory that contains opencollection.yml.
Changed test execution to cd into each collection directory before running tests.

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

.github/workflows/api-tests.yml

@@ -61,13 +61,15 @@ jobs:
             echo "Spouštím testy pro: $dir"
             echo "=========================================="
             
-            # Spust testy a zachyt výsledek
+            # Přepnout do složky kolekce a spustit testy
-            if npx @usebruno/cli run "${dir#apiTest/}" -r; then
+            cd "$dir"
+            if npx @usebruno/cli run -r; then
               echo "✅ Testy pro $(basename $dir) prošly"
             else
               echo "❌ Testy pro $(basename $dir) selhaly"
               ALL_PASSED=false
             fi
+            cd ../..
           done
           
           echo "=========================================="