fix: force canvas redraw after BPM duration recalculation

app/static/js/app.precompiled.js

@@ -167,7 +167,8 @@ const computeLengthBars=(tracksArr,spb)=>{let maxSec=0;(tracksArr||[]).forEach(t
 const scanForSections=tracks=>{(tracks||[]).forEach(t=>{if(t.sections){t.sections.forEach(s=>{const secId=s.sectionId||s.id;if(s.tracks&&!sectionStore[secId]){sectionStore[secId]={id:secId,name:s.name,is_root:false,length_bars:computeLengthBars(s.tracks,secondsPerBar),auto_compute_length:true,tracks:serializeTracksList(s.tracks,secondsPerBar),color:s.color||null};}if(s.tracks){scanForSections(s.tracks);}});}});};scanForSections(tracksList);const subTabs=(subTabsList||[]).map(st=>{return{id:st.id,label:st.label,type:st.type,track_id:st.trackId,target_id:st.target_id,parent_tab_id:st.parent_tab_id,notes:st.notes||[],duration:st.duration||4,instrument_program:st.instrumentProgram,instrument_name:st.instrumentName,current_time:st.currentTime||0,color:st.color||null};});return{project_id:projectId||'proj_'+Date.now(),metadata:{title:name||"Dự án mới",bpm:parseFloat(bpmVal||120),time_signature_numerator:4,time_signature_denominator:4,sample_rate:44100},main_session:{id:"main",name:"MAIN SESSION",is_root:true,length_bars:(()=>{let maxBar=16.0;(mainTracks||[]).forEach(t=>{(t.items||[]).forEach(item=>{const end=(item.start_bar||0)+(item.duration_bars||4);if(end>maxBar)maxBar=end;});});return maxBar;})(),auto_compute_length:true,tracks:mainTracks},sub_tabs:subTabs,section_store:sectionStore};};const deserializeProjectFromSchema=schemaObj=>{const bpmVal=schemaObj.metadata?schemaObj.metadata.bpm:120;const secondsPerBar=60.0/bpmVal*4;const sectionStore=schemaObj.section_store||{};const restoredTracks=deserializeTracksList(schemaObj.main_session.tracks,secondsPerBar,sectionStore);const restoredSessionTabs=[];Object.keys(sectionStore).forEach(secId=>{const secContainer=sectionStore[secId];const secTracks=deserializeTracksList(secContainer.tracks,secondsPerBar,sectionStore);restoredSessionTabs.push({id:'session_'+secId,name:secContainer.name,sectionId:secId,tracks:secTracks,length_bars:secContainer.length_bars||16.0,auto_compute_length:secContainer.auto_compute_length!==undefined?secContainer.auto_compute_length:true,color:secContainer.color||null});});const restoredSubTabs=(schemaObj.sub_tabs||[]).map(st=>{return{id:st.id,label:st.label,type:st.type,trackId:st.track_id,target_id:st.target_id,parent_tab_id:st.parent_tab_id,notes:st.notes||[],duration:st.duration||4,instrumentProgram:st.instrument_program,instrumentName:st.instrument_name,currentTime:st.current_time||0,color:st.color||null};});return{bpm:bpmVal,tracks:restoredTracks,sessionTabs:restoredSessionTabs,subTabs:restoredSubTabs};};const App=()=>{// ── State Definitions ──
 const[tracks,setTracks]=useState([{id:'1',name:'Track 01',buffer:null,startTime:0,volumeDb:0,pan:0,muted:false,solo:false,color:'#0f766e',markers:[],serverFileId:null,clips:[],sections:[],midiItems:[],isArmed:false,monitoringEnabled:true,inputSource:{deviceType:'NONE',deviceId:''}},{id:'2',name:'Track 02',buffer:null,startTime:0,volumeDb:0,pan:0,muted:false,solo:false,color:'#1d4ed8',markers:[],serverFileId:null,clips:[],sections:[],midiItems:[],isArmed:false,monitoringEnabled:true,inputSource:{deviceType:'NONE',deviceId:''}}]);const[appWarningModal,setAppWarningModal]=useState(null);const[bpm,setBpm]=useState(localStorage.getItem('studio_bpm')||'120');const prevBpmRef=useRef(bpm);const[draggedClip,setDraggedClip]=useState(null);const[hoveredTrackId,setHoveredTrackId]=useState(null);// Recalculate item/section/selection durations when BPM changes
 useEffect(()=>{const oldSpb=prevBpmRef.current?60.0/parseFloat(prevBpmRef.current)*4:null;const bpmVal=parseFloat(bpm)||120;const secondsPerBar=60.0/bpmVal*4;// Recalculate range loop selection to maintain bar count
-if(oldSpb&&selectionStart!==null&&selectionEnd!==null&&selectionEnd>selectionStart){const startBar=selectionStart/oldSpb;const endBar=selectionEnd/oldSpb;if(endBar-startBar>0.01){setSelectionStart(startBar*secondsPerBar);setSelectionEnd(endBar*secondsPerBar);}}prevBpmRef.current=bpm;// Recalculate item/section durations
+if(oldSpb&&selectionStart!==null&&selectionEnd!==null&&selectionEnd>selectionStart){const startBar=selectionStart/oldSpb;const endBar=selectionEnd/oldSpb;if(endBar-startBar>0.01){setSelectionStart(startBar*secondsPerBar);setSelectionEnd(endBar*secondsPerBar);}}prevBpmRef.current=bpm;// Force canvas redraw
+setCanvasRedrawCount(n=>n+1);// Recalculate item/section durations
 updateActiveTracks(prev=>prev.map(t=>({...t,midiItems:(t.midiItems||[]).map(m=>{if(m.length_bars)return{...m,duration:m.length_bars*secondsPerBar};if(m.duration){// Legacy item without length_bars: compute bars from current duration/BPM
 const bars=Math.max(0.25,Math.round(m.duration/secondsPerBar*4)/4);return{...m,length_bars:bars,duration:bars*secondsPerBar};}return m;}),sections:(t.sections||[]).map(s=>{if(s.length_bars)return{...s,duration:s.length_bars*secondsPerBar};if(s.duration){const bars=Math.max(0.25,Math.round(s.duration/secondsPerBar*4)/4);return{...s,length_bars:bars,duration:bars*secondsPerBar};}return s;})})));},[bpm]);const openPanel=id=>{if(id==='export')setShowExportPanel(true);else if(id==='ai')setShowAIPanel(true);else if(id==='python_tools')setShowPythonToolsPanel(true);else if(id==='selection')setShowSelectionPanel(true);};const[instrumentSelectorTrackId,setInstrumentSelectorTrackId]=useState(null);const[fxSelectorTrackId,setFxSelectorTrackId]=useState(null);const handleSetTrackFx=(trackId,fxType)=>{updateActiveTracks(prev=>prev.map(t=>t.id===trackId?{...t,fxType}:t));setFxSelectorTrackId(null);setTimeout(()=>lucide.createIcons(),50);};const[instrumentSelectorData,setInstrumentSelectorData]=useState(null);const openInstrumentSelector=trackId=>{setInstrumentSelectorTrackId(trackId);setSfPresetSearchQuery('');const track=activeTracks.find(t=>t.id===trackId);if(track&&track.instrumentId&&track.instrumentId.startsWith('sf_')){// Track already has a SoundFont assigned → open instrument selection directly
 setSynthCategory('soundfont');setSelectedSoundFontId(track.instrumentId);setSfPresets(null);const sfIdParam=track.instrumentId.replace('sf_','');window.SonicAPI.listSoundfontInstruments(sfIdParam).then(data=>setSfPresets(data.presets||[])).catch(()=>setSfPresets([]));}else{// Reset synth state and always reload plugin data