feat(database): full-page database conversion (Notion-style)

- Migration: add collection_id column to pages table
- POST /api/pages/{id}/convert-to-database: transforms page into database
- GET /api/collections/{id}/table-data: returns props + pages for table view
- POST /api/collections/{id}/pages: creates new row in collection
- New page_editor_collection.html template for database view
- _database_table.html: Notion-style table with columns, rows, New Page, Add Property
- Alpine.js component for cell editing, new page creation, property mgmt
- CSS: complete database table styling (view bar, table, cells, modals, dropdowns)
- Frontend: createDatabase() now converts page to full-page DB (was inline embed)

app/templates/_page_editor_scripts.html

@@ -325,20 +325,19 @@
         // ── v4.5.0+: Get Started actions ──
         inlineDBs:[],
         async createDatabase(){
-          const name=prompt('Database name:','New Database');
+          const name=prompt('Database name:',this.pageTitle||'New Database');
           if(!name||!name.trim())return;
           const csrf=document.cookie.match(/csrf_token=([^;]+)/);
           try{
-            const r=await fetch('/db/inline/api',{
+            const r=await fetch(`/api/pages/${this.pid}/convert-to-database`,{
               method:'POST',headers:{'Content-Type':'application/json','X-CSRF-Token':csrf?csrf[1]:''},
-              body:JSON.stringify({name:name.trim(),parent_page_id:this.pid})
+              body:JSON.stringify({name:name.trim()})
             });
             const d=await r.json();
-            if(d.id){
-              this.inlineDBs.push({id:d.id,name:d.name,view_type:'table'});
-              this.showToast('Database created — '+d.name);
-              this.saveDBsToPage();
-              this.renderInlineDBs();
+            if(d.status==='converted'){
+              this.showToast('Database created — reloading...');
+              // Reload to show the database table view
+              setTimeout(()=>{window.location.href=d.view_url;},500);
             }else{
               this.showToast('Failed to create database');
             }