fix: « Turn into » du menu contextuel ne fonctionnait pas (v7.59.3)

- cause : la garde de turnInto() faisait _BLOCK_TURN_TYPES.indexOf(type) sur
  un tableau d'objets {id,name} → toujours -1 → retour immédiat après
  l'ouverture du sous-menu, aucun changement de format
- correction : validation par id (_BLOCK_TURN_TYPES.some(t=>t.id===type))
- même fonction : convertir un texte en To-do / Toggle vidait le contenu
  (exclusion par erreur) ; seuls les types sans champ texte (image, embed,
  meeting, divider, table_of_contents, database, button, columns) le vident
- tests : tests/test_v7593_turn_into.py (4 tests, dont 1 comportemental node
  qui exécute la vraie turnInto() extraite de la source)
- livraison : VERSION + app/main = 7.59.3, OpenAPI 525 chemins, CHANGELOG

static/js/page_editor_scripts.js

@@ -1523,7 +1523,7 @@ replaceBlock(idx,type){const b=this.blocks[idx];if(!b)return;this.sync();this.pu
 
         // ── v5.10.0: Turn into / couleurs / liens / déplacement ──
         _blockTargets(idx){const sel=_selIndicesSorted();return(sel.includes(idx))?sel:[idx];},
-        turnInto(idx,type){if(idx<0||idx>=this.blocks.length)return;if(_BLOCK_TURN_TYPES.indexOf(type)<0)return;const targets=this._blockTargets(idx);const focusId=this.blocks[idx].id;this.sync();this.pushHistory();targets.forEach(i=>{const b=this.blocks[i];if(!b)return;if(b.type===type)return;const keep=(b.content||'').trim();b.type=type;if(type!=='to_do'&&type!=='toggle'&&keep&&['image','embed','meeting','divider','table_of_contents','database','button','columns'].indexOf(b.type)<0){b.content=keep;}else{b.content='';}if(type==='toggle'){b.expanded=true;if(!Array.isArray(b.children))b.children=[];}if(type==='to_do')b.checked=false;if(type==='table'&&!Array.isArray(b.rows))b.rows=_tblNew(3,3);if(type==='code'&&!b.language)b.language='Plain Text';if(type==='columns'&&(!Array.isArray(b.children)||!b.children.length))b.children=[{id:genId(),type:'paragraph',content:''}];if(type==='button'){b.automation_id=0;b.automation_name='';}});
+        turnInto(idx,type){if(idx<0||idx>=this.blocks.length)return;if(!_BLOCK_TURN_TYPES.some(t=>t.id===type))return;const targets=this._blockTargets(idx);const focusId=this.blocks[idx].id;this.sync();this.pushHistory();targets.forEach(i=>{const b=this.blocks[i];if(!b)return;if(b.type===type)return;const keep=(b.content||'').trim();b.type=type;if(keep&&['image','embed','meeting','divider','table_of_contents','database','button','columns'].indexOf(b.type)<0){b.content=keep;}else{b.content='';}if(type==='toggle'){b.expanded=true;if(!Array.isArray(b.children))b.children=[];}if(type==='to_do')b.checked=false;if(type==='table'&&!Array.isArray(b.rows))b.rows=_tblNew(3,3);if(type==='code'&&!b.language)b.language='Plain Text';if(type==='columns'&&(!Array.isArray(b.children)||!b.children.length))b.children=[{id:genId(),type:'paragraph',content:''}];if(type==='button'){b.automation_id=0;b.automation_name='';}});
           this.dirty=true;this.autoSave();this.render();_rtSync();_selClear();
           setTimeout(()=>{const bid=this.blocks[idx]?this.blocks[idx].id:focusId;if(type==='table'){_tblFocus(bid,0,0);}else{const el=this.getEl(bid);if(el){el.focus();ce(el);}}},60);},
         setBlockColor(idx,key,val){if(idx<0||idx>=this.blocks.length)return;const targets=this._blockTargets(idx);const v=(!val||val==='default')?null:val;this.sync();this.pushHistory();targets.forEach(i=>{const b=this.blocks[i];if(!b)return;if(!b.style)b.style={};if(v==null)delete b.style[key];else b.style[key]=v;});this.dirty=true;this.autoSave();this.render();_rtSync();_selClear();},