fix(recipes): steps shown as raw JSON when AI uses instruction/appliance_function objects

- _stepStr: parse JSON-string steps; handle s.instruction key (backward-compat with already-saved recipes)
- _stepAppliance: new helper to extract appliance_function hint; returns null for 'Nessuno'/'None'
- renderRecipe steps list: shows appliance badge inline after step text when present
- CSS: .recipe-step-appliance badge (green chip, dark-mode variant)
- Prompt (both generateRecipe + generateRecipeStream): rule 9/10 explicitly forbids step objects;
  appliance info must be embedded in the step text string directly

assets/css/style.css

@@ -4276,6 +4276,19 @@ body.server-offline .bottom-nav {
     color: #3730a3;
     white-space: nowrap;
 }
+/* Appliance/mode badge shown inline next to a step text */
+.recipe-step-appliance {
+    display: inline-block;
+    margin-left: 6px;
+    background: #f0fdf4;
+    border: 1px solid #bbf7d0;
+    border-radius: 12px;
+    padding: 1px 8px;
+    font-size: 0.72rem;
+    color: #15803d;
+    vertical-align: middle;
+    white-space: nowrap;
+}
 
 /* Recipe ingredient use buttons */
 .recipe-ingredients {
@@ -7653,6 +7666,7 @@ body.cooking-mode-active .app-header {
 [data-theme="dark"] .recipe-expiry-note  { background: #2a1e00; color: #fde68a; }
 [data-theme="dark"] .recipe-tools-banner { background: #1a1040; border-color: #3730a3; color: #c4b5fd; }
 [data-theme="dark"] .recipe-tool-chip    { background: #2e1a4a; color: #c4b5fd; }
+[data-theme="dark"] .recipe-step-appliance { background: #052e16; border-color: #166534; color: #4ade80; }
 [data-theme="dark"] .recipe-subtype-chip { background: #1c1300; border-color: #78350f; color: var(--text); }
 [data-theme="dark"] .recipe-subtype-chip:has(input:checked) { background: #2a1e00; border-color: #d97706; }