Adom Gantt

@@ -3,6 +3,84 @@ Decisions taken while building, and the places where the plan and the code disagreed. Newest first. +## Build notes, 2026-08-11 (0.20.0, redo)++Ctrl+Shift+Z, and Ctrl+Y as its Windows alias. A minor rather than a patch: a redo+stack is a new capability and a new piece of module state, not a fix.++**Undo and redo are one implementation pointed in opposite directions.** The old+`undo()` was a seven-branch restore that wrote state and returned. It is now+`applySnapshot(sn)`, which does the same restore but first captures its own inverse+from the CURRENT state and returns it. `timeTravel(from,to,...)` pops an entry off+one stack, applies it, and pushes the inverse onto the other. `undo()` and `redo()`+are one line each and differ only in which stack is which. Two hand-written halves+would have drifted the first time a snapshot type gained a field; this cannot,+because there is only one half.++Create and delete are the one pair that cannot capture their inverse beforehand:+applying a `delete` entry restores the row, and the thing that undoes THAT is a+`create` entry, so each returns the other's shape. They act on the same object, so+a create, an undo and a redo hand back a row with the id and the stable key it was+born with, and everything keyed on them still resolves. Measured: the created row+comes back as `identity-probe`, a later owner edit lands on it, and it is in the+sidecar's `added` list.++**Any new edit clears the redo stack**, because redo replays what undo took back+and must never invent history. That rule lives in one place: `pushUndo()`, which+every one of the nine edit-recording sites now calls, replacing nine copies of the+same push-and-trim. The tenth site, added later by someone else, gets the rule for+free. `undo()` and `redo()` deliberately do NOT go through it: time travel is the+one thing that must not clear the other stack.++**The units stay symmetric.** One press of Alt+Arrow is one undo entry and one redo+entry; the 600ms coalescing from 0.17.0 is a changelog concern and never touched+the stack. Measured: four presses moved a row four slots, took four undos to put+back and four redos to reapply.++**The changelog needed no server change.** The markdown renderer already appends+the `via` in brackets to every line, so a redo reads as+`user reordered rows: hw-pcb-reflow, hw-wc-power (redo)` exactly as an undo reads+`(undo)` today. An agent reading the log sees both directions in the order they+happened.++**Guarded by construction rather than by a second rule.** Redo sits in the same+document keydown handler as undo, so whatever stops Ctrl+Z from firing stops+Ctrl+Shift+Z too. Every text surface in this app already stops its own keydown, so+inside a cell editor, the create panel or the filter box the FIELD's native undo and+redo win and the app never sees the chord. Verified: with a notes editor open and+text typed into it, Ctrl+Shift+Z and Ctrl+Z leave the editor open and the plan+untouched, and the app's own undo works again the moment the field is closed.++**Ctrl+Y is taken as an alias.** Nothing in this app claims it and no browser binds+it, and inside a field the field's handler stops it before it arrives, so it costs+one clause for a keystroke half the users will reach for. Verified end to end.++**Evidence.** Fifteen action types driven do, undo, redo, undo, redo, each compared+by deep equality of the merged plan (`/export/json`, read after the save debounce so+it is committed truth and not a screen reading): owner, status, notes, deadline,+rename, provenance, phase move, Alt+Arrow move, delete, create, milestone rename,+snapped bar drag, chart row reorder, lane drag, whole-plan shift. Every one restores+to the pre-edit state on undo, returns to the post-edit state on redo, and does it+again on the second round trip. Plus: a new edit made after an undo leaves Ctrl+Z's+redo a no-op; the lane drag moves the whole Hardware block to the end of the plan+and comes back exactly; the changelog carries 52 undo and 31 redo events+interleaved in the order they happened and renders `(redo)` in the markdown.++**One measurement note.** The 52-key fingerprint appeared to move in three keys+beyond the version, `svgLen` and the today tag's position and date. It was the clock:+this session ran past midnight and the date rolled from 10-Aug to 11-Aug, which moves+the today marker. Proven rather than assumed, by pulling the shipped 0.19.0+`gantt.html` back out of the page repo with `adom-wiki repo show --ref` and+fingerprinting it against 0.20.0 under the same clock and the same version string:+zero diff on all 52 keys. Worth keeping: a fingerprint over a plan with a today+marker is only stable within a day, and the control run is how you tell the clock+from the code.++**Also worth keeping.** A scratch instance was briefly pointed at a port already+held by an unrelated app in this container, and the harness happily scraped that+app's page and reported nothing. The runner now checks the log for `EADDRINUSE` and+confirms the served page is ours before it trusts a single number.+ ## Build notes, 2026-08-10 (0.19.0, arrow keys walk the table)  "Up down arrow keys should move which row is selected. Hitting Enter on a row

@@ -1044,20 +1044,30 @@ let depSvg;  // ── Undo ── const undoStack = [];+// Redo only ever replays what undo just took back. It never invents history, so+// any new edit empties it: that is the whole contract, and it lives in pushUndo+// rather than at each of the nine places that record an edit, because the tenth+// one added later would have forgotten.+const redoStack = [];+function pushUndo(sn){+  undoStack.push(sn);+  if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);+  redoStack.length=0;+}+const UNDO_TOAST_DEFAULT='Undid change &middot; <kbd>Ctrl+Z</kbd>'; let undoTimer = null; // The snapshot carries owner, status and description too, so a table edit is one // Ctrl+Z like every other edit rather than a second class of change.-function snapshotMany(ids){ids.forEach(id=>{const r=items.find(d=>d.id===id);if(r)undoStack.push({type:'edit',id,s:r.start,e:r.end,deps:r.deps?[...r.deps]:[],note:r.note||'',owner:r.owner,status:r.status,desc:r.description,prov:r.provenance,name:r.name});});if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);}+function snapshotMany(ids){ids.forEach(id=>{const r=items.find(d=>d.id===id);if(r)pushUndo({type:'edit',id,s:r.start,e:r.end,deps:r.deps?[...r.deps]:[],note:r.note||'',owner:r.owner,status:r.status,desc:r.description,prov:r.provenance,name:r.name});});} function snapshot(id){snapshotMany([id]);} // One undo entry covering many rows, for bulk operations like a plan shift. function snapshotGroup(ids){   const entries=[];   ids.forEach(id=>{const r=items.find(d=>d.id===id);if(r)entries.push({id,s:r.start,e:r.end,deps:r.deps?[...r.deps]:[],note:r.note||''});});   const ms=items.filter(r=>r.type==='milestone');-  undoStack.push({type:'group',entries,ms:ms.map(r=>({r,date:r.date})),phases:phases.map(p=>({p,start:p.start,end:p.end}))});-  if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);+  pushUndo({type:'group',entries,ms:ms.map(r=>({r,date:r.date})),phases:phases.map(p=>({p,start:p.start,end:p.end}))}); }-function snapshotOrder(){undoStack.push({type:'order',order:items.map(rowOrderKey)});if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);}+function snapshotOrder(){pushUndo({type:'order',order:items.map(rowOrderKey)});} // Legacy label and name keys are still accepted, so an order saved before row // keys became stable still restores. function orderKeyMap(){@@ -1257,8 +1267,7 @@ function moveFocusedRow(dir){     else if(res==='edge')flash(saveInd,sorted?'the end of the tied group':'the end of the plan');     return;   }-  undoStack.push({type:'phase',r,phase:fromPhase,order});-  if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);+  pushUndo({type:'phase',r,phase:fromPhase,order});   const np=phaseAtPosition(r);   if(np!==undefined&&np!==r.phase){     r.phase=np;@@ -1272,10 +1281,18 @@ function moveFocusedRow(dir){   moveHint='"'+(r.name||'a row')+'"';   scheduleKeyMoveSave(); }-function undo(){-  if(!undoStack.length)return;-  const sn=undoStack.pop();+// Apply a snapshot, and return the snapshot that puts things back. Undo and redo+// are the same operation pointed in opposite directions, so there is exactly one+// implementation of "restore this state" and the two directions cannot drift+// apart the way two hand-written halves would. Every branch captures its own+// inverse from the CURRENT state before it overwrites it, except create and+// delete, which are each other's inverse and take it from what removeRow returns.+// Returns null when the snapshot no longer resolves, which is the old early+// return: a stale entry does nothing rather than half-applying.+function applySnapshot(sn){   if(sn.type==='order'){+    const inv={type:'order',order:items.map(rowOrderKey),+      phases:(sn.phases||[]).map(pc=>({r:pc.r,from:pc.r.phase}))};     (sn.phases||[]).forEach(pc=>{       pc.r.phase=pc.from;       if(pc.r.id&&barEls[pc.r.id])barEls[pc.r.id].bar.style.background=phaseColor(pc.from);@@ -1283,39 +1300,89 @@ function undo(){     });     applyOrder(sn.order);     if(sn.phases&&sn.phases.length){applyCollapse();applyFilter();refreshChartGeometry();}+    return inv;+  }+  if(sn.type==='delete'){+    restoreRow(sn.r,sn.idx,sn.droppedDeps);+    // Putting the row back is undone by taking it out again, and it is the SAME+    // object, so its id and its stable key survive the round trip and everything+    // keyed on them still resolves.+    return {type:'create',r:sn.r};   }-  else if(sn.type==='delete'){restoreRow(sn.r,sn.idx,sn.droppedDeps);}-  else if(sn.type==='create'){removeRow(sn.r);renderTable();}-  else if(sn.type==='phase'){+  if(sn.type==='create'){+    const info=removeRow(sn.r); renderTable();+    return {type:'delete',r:sn.r,idx:info?info.idx:items.length,droppedDeps:info?info.droppedDeps:[]};+  }+  if(sn.type==='phase'){+    const inv={type:'phase',r:sn.r,phase:sn.r.phase,order:items.map(rowOrderKey)};     sn.r.phase=sn.phase;     if(sn.r.id&&barEls[sn.r.id])barEls[sn.r.id].bar.style.background=phaseColor(sn.phase);     if(sn.r._msLine)sn.r._msLine.style.color=phaseColor(sn.phase);     applyOrder(sn.order);applyFilter();refreshChartGeometry();+    return inv;   }-  else if(sn.type==='ms'){-    sn.r.date=sn.date;-    if(sn.name!==undefined)sn.r.name=sn.name;-    setOpt(sn.r,'owner',sn.owner);setOpt(sn.r,'status',sn.status);setOpt(sn.r,'description',sn.desc);-    if('prov' in sn)setProv(sn.r,sn.prov);-    refreshMsChrome(sn.r);updateMilestone(sn.r);+  if(sn.type==='ms'){+    const r=sn.r;+    const inv={type:'ms',r,date:r.date,name:r.name,owner:r.owner,status:r.status,desc:r.description,prov:r.provenance};+    r.date=sn.date;+    if(sn.name!==undefined)r.name=sn.name;+    setOpt(r,'owner',sn.owner);setOpt(r,'status',sn.status);setOpt(r,'description',sn.desc);+    if('prov' in sn)setProv(r,sn.prov);+    refreshMsChrome(r);updateMilestone(r);+    return inv;   }-  else if(sn.type==='group'){-    // one Ctrl+Z undoes the whole shift, not 26 tasks one at a time+  if(sn.type==='group'){+    // one Ctrl+Z undoes the whole shift, not 26 tasks one at a time, and one+    // Ctrl+Shift+Z puts the whole shift back+    const inv={type:'group',+      entries:sn.entries.map(en=>{const r=items.find(d=>d.id===en.id);+        return r?{id:en.id,s:r.start,e:r.end,deps:r.deps?[...r.deps]:[],note:r.note||''}:Object.assign({},en);}),+      ms:(sn.ms||[]).map(m=>({r:m.r,date:m.r.date})),+      phases:(sn.phases||[]).map(x=>({p:x.p,start:x.p.start,end:x.p.end}))};     sn.entries.forEach(en=>{const r=items.find(d=>d.id===en.id);if(!r)return;r.start=en.s;r.end=en.e;r.deps=en.deps;r.note=en.note;});     (sn.ms||[]).forEach(m=>{m.r.date=m.date;});     (sn.phases||[]).forEach(x=>{x.p.start=x.start;x.p.end=x.end;});     rebuildTimeline();Object.keys(barEls).forEach(id=>updateBar(id));+    return inv;   }-  else{const r=items.find(d=>d.id===sn.id);if(!r)return;r.start=sn.s;r.end=sn.e;r.deps=sn.deps;if(sn.note!==undefined)r.note=sn.note;-    if('owner' in sn)setOpt(r,'owner',sn.owner);-    if('status' in sn)setOpt(r,'status',sn.status);-    if('desc' in sn)setOpt(r,'description',sn.desc);-    if('prov' in sn)setProv(r,sn.prov);-    if(sn.name!==undefined)r.name=sn.name;-    updateBar(sn.id);refreshLabelRow(r);refreshChartGeometry();}+  const r=items.find(d=>d.id===sn.id);+  if(!r)return null;+  const inv={type:'edit',id:sn.id,s:r.start,e:r.end,deps:r.deps?[...r.deps]:[],note:r.note||'',+             owner:r.owner,status:r.status,desc:r.description,prov:r.provenance,name:r.name};+  r.start=sn.s;r.end=sn.e;r.deps=Array.isArray(sn.deps)?[...sn.deps]:sn.deps;+  if(sn.note!==undefined)r.note=sn.note;+  if('owner' in sn)setOpt(r,'owner',sn.owner);+  if('status' in sn)setOpt(r,'status',sn.status);+  if('desc' in sn)setOpt(r,'description',sn.desc);+  if('prov' in sn)setProv(r,sn.prov);+  if(sn.name!==undefined)r.name=sn.name;+  updateBar(sn.id);refreshLabelRow(r);refreshChartGeometry();+  return inv;+}+// One step in either direction. The entry comes off one stack and its inverse+// goes onto the other, which is what makes undo, redo, undo land exactly where+// undo did. Note that neither of these goes through pushUndo: time travel is the+// one thing that must NOT clear the other stack.+function timeTravel(from,to,via,label,chord){+  if(!from.length)return false;+  const sn=from.pop();+  const inv=applySnapshot(sn);+  if(inv===null)return false;+  to.push(inv);+  if(to.length>100)to.splice(0,to.length-100);   if(prefs.view==='table')renderTable();-  clearTimeout(undoTimer);undoToast.classList.add('show');undoTimer=setTimeout(()=>undoToast.classList.remove('show'),1800);scheduleSave('undo');+  clearTimeout(undoTimer);+  undoToast.innerHTML=label+' &middot; <kbd>'+chord+'</kbd>';+  undoToast.classList.add('show');+  undoTimer=setTimeout(()=>{undoToast.classList.remove('show');undoToast.innerHTML=UNDO_TOAST_DEFAULT;},1800);+  // Tagged so the changelog says which direction it was. The markdown renderer+  // already puts the via in brackets on every line, so this reads as+  // "user reassigned X from A to B (redo)" with no server change.+  scheduleSave(via);+  return true; }+function undo(){ return timeTravel(undoStack,redoStack,'undo','Undid change','Ctrl+Z'); }+function redo(){ return timeTravel(redoStack,undoStack,'redo','Redid change','Ctrl+Shift+Z'); } // Is anything at all in progress? A chord that opens a panel must never fire in // the middle of something else, and "something else" includes any field anywhere, // not just this app's own editors.@@ -1334,7 +1401,21 @@ function appIsIdle(){ } function wireGlobalKeys(){ document.addEventListener('keydown',e=>{-  if((e.ctrlKey||e.metaKey)&&e.key==='z'){e.preventDefault();undo();}+  // Undo and redo live in the same handler and are therefore guarded identically,+  // which is the point: whatever stops Ctrl+Z from firing stops Ctrl+Shift+Z too.+  // Every text surface in this app stops its own keydown, so inside a cell editor,+  // the create panel or the filter box the FIELD's native undo and redo win and+  // this never runs.+  if((e.ctrlKey||e.metaKey)&&(e.key==='z'||e.key==='Z')){+    e.preventDefault();+    if(e.shiftKey)redo(); else undo();+    return;+  }+  // Ctrl+Y is the Windows redo chord. Nothing in this app claims it and no browser+  // binds it, so it is one clause for a keystroke half our users will reach for.+  if((e.ctrlKey||e.metaKey)&&!e.shiftKey&&(e.key==='y'||e.key==='Y')){+    e.preventDefault(); redo(); return;+  }   // Alt+Up and Alt+Down MOVE a row. Checked first, so the two arrow meanings never   // race: with Alt the plan changes, without it only the selection does.   if(e.altKey&&!e.ctrlKey&&!e.metaKey&&(e.key==='ArrowUp'||e.key==='ArrowDown')){@@ -2295,8 +2376,7 @@ function updateMilestone(r){   drawDeps(); } function snapshotMs(r){-  undoStack.push({type:'ms',r,date:r.date,name:r.name,owner:r.owner,status:r.status,desc:r.description,prov:r.provenance});-  if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);+  pushUndo({type:'ms',r,date:r.date,name:r.name,owner:r.owner,status:r.status,desc:r.description,prov:r.provenance}); } // Milestone chrome that is not the date: the label row, the tooltip body and the // dashed rule's tag all restate the milestone, so they move together.@@ -2665,6 +2745,7 @@ $('btnHelp').addEventListener('click',e=>{     <div class="dd-sep"></div>     <div class="dd-label">keyboard</div>     <div class="dd-item" style="cursor:default"><span style="color:var(--accent);min-width:90px;font-family:'JetBrains Mono',monospace;font-size:10px">Ctrl+Z</span>Undo</div>+    <div class="dd-item" style="cursor:default"><span style="color:var(--accent);min-width:90px;font-family:'JetBrains Mono',monospace;font-size:10px">Ctrl+Shift+Z</span>Redo, also Ctrl+Y. Any new edit clears it</div>     <div class="dd-item" style="cursor:default"><span style="color:var(--accent);min-width:90px;font-family:'JetBrains Mono',monospace;font-size:10px">Up/Down</span>Move the selected row in the table. The pane only scrolls to keep it in view</div>     <div class="dd-item" style="cursor:default"><span style="color:var(--accent);min-width:90px;font-family:'JetBrains Mono',monospace;font-size:10px">Enter</span>Edit the selected row's name. In a cell, commit and step down a row</div>     <div class="dd-item" style="cursor:default"><span style="color:var(--accent);min-width:90px;font-family:'JetBrains Mono',monospace;font-size:10px">Shift+N</span>New task or milestone</div>@@ -2677,7 +2758,7 @@ $('btnHelp').addEventListener('click',e=>{     <div class="dd-item" style="cursor:default"><span style="color:var(--accent);min-width:90px;font-family:'JetBrains Mono',monospace;font-size:10px">click deps</span>Toggle dependency arrows</div>     <div class="dd-sep"></div>     <div class="dd-label">data</div>-    <div class="dd-item" style="cursor:default"><span style="color:var(--text-body);font-size:10px">Edits auto-save to sidecar JSON. Ctrl+Z undoes up to 100 steps.</span></div>`;+    <div class="dd-item" style="cursor:default"><span style="color:var(--text-body);font-size:10px">Edits auto-save to sidecar JSON. Ctrl+Z undoes up to 100 steps, Ctrl+Shift+Z puts them back.</span></div>`;   exportMenu.style.left=Math.min(rect.right-220,window.innerWidth-240)+'px';exportMenu.style.top=(rect.bottom+4)+'px';exportMenu.classList.add('show');   e.stopPropagation(); });@@ -2914,8 +2995,7 @@ function openCreateEditor(){     lastCreated={owner:owner||'', start, end};     addedItems.push(r);     insertRow(r);-    undoStack.push({type:'create',r});-    if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);+    pushUndo({type:'create',r});     closeEditor();     renderTable();     rebuildTimeline();          // a new date can widen the axis@@ -3601,8 +3681,7 @@ function endRowDrag(commit){   const fromPhase=r.phase;   const toPhase=target.phase;   // One undo for the whole gesture, position and lane together.-  undoStack.push({type:'phase',r,phase:fromPhase,order:items.map(rowOrderKey)});-  if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);+  pushUndo({type:'phase',r,phase:fromPhase,order:items.map(rowOrderKey)});   const cur=items.indexOf(r);   if(cur<0)return;   items.splice(cur,1);@@ -3884,8 +3963,7 @@ function commitCell(r,field,v){     const np=parseInt(v,10);     if(!phases[np]||np===r.phase)return;     // One undo step covers both halves: the field and the re-homing it causes.-    undoStack.push({type:'phase',r,phase:r.phase,order:items.map(rowOrderKey)});-    if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);+    pushUndo({type:'phase',r,phase:r.phase,order:items.map(rowOrderKey)});     moveRowToPhase(r,np);     scheduleSave('table-edit');     return;@@ -3951,13 +4029,12 @@ function deleteRow(r){   if(focusedKey===rowKey(r))focusedKey=null;   const info=removeRow(r);   if(!info)return;-  undoStack.push({type:'delete',r,idx:info.idx,droppedDeps:info.droppedDeps});-  if(undoStack.length>100)undoStack.splice(0,undoStack.length-100);+  pushUndo({type:'delete',r,idx:info.idx,droppedDeps:info.droppedDeps});   renderTable();   clearTimeout(undoTimer);   undoToast.innerHTML='Deleted '+esc(label)+' &middot; <kbd>Ctrl+Z</kbd>';   undoToast.classList.add('show');-  undoTimer=setTimeout(()=>{undoToast.classList.remove('show');undoToast.innerHTML='Undid change &middot; <kbd>Ctrl+Z</kbd>';},3200);+  undoTimer=setTimeout(()=>{undoToast.classList.remove('show');undoToast.innerHTML=UNDO_TOAST_DEFAULT;},3200);   scheduleSave('table-delete'); } function wireTableFilters(){