perf: optimize CaDecon iteration hot paths

apps/cadecon/src/App.tsx

@@ -13,6 +13,7 @@ import { getBridgeUrl, startBridgeHeartbeat } from '@calab/io';
 import { trackEvent } from '@calab/community';
 import { supabaseEnabled, user, authLoading } from './lib/community/index.ts';
 import { CaDeconHeader } from './components/layout/CaDeconHeader.tsx';
+import { ResizableGrid } from './components/layout/ResizableGrid.tsx';
 import { ImportOverlay } from './components/layout/ImportOverlay.tsx';
 import { RasterOverview } from './components/raster/RasterOverview.tsx';
 import { SubsetConfig } from './components/controls/SubsetConfig.tsx';
@@ -145,7 +146,7 @@ const App: Component = () => {
             </>
           }
         >
-          <div class="viz-grid">
+          <ResizableGrid>
             <DashboardPanel id="raster" variant="data" class="viz-grid__col--raster raster-panel">
               <p class="panel-label">Raster Overview</p>
               <RasterOverview />
@@ -168,7 +169,7 @@ const App: Component = () => {
               <p class="panel-label">Trace Inspector</p>
               <TraceInspector />
             </DashboardPanel>
-          </div>
+          </ResizableGrid>
           <IterationScrubber />
         </VizLayout>
       </DashboardShell>

apps/cadecon/src/components/distributions/HistogramCard.tsx

@@ -22,8 +22,13 @@ export interface HistogramCardProps {
 function computeBins(values: number[], binCount: number): { centers: number[]; counts: number[] } {
   if (values.length === 0) return { centers: [], counts: [] };
 
-  const min = Math.min(...values);
-  const max = Math.max(...values);
+  let min = values[0];
+  let max = values[0];
+  for (let i = 1; i < values.length; i++) {
+    const v = values[i];
+    if (v < min) min = v;
+    if (v > max) max = v;
+  }
   const range = max - min || 1;
   const binWidth = range / binCount;
 

apps/cadecon/src/components/layout/ResizableGrid.tsx

@@ -0,0 +1,79 @@
+import { createSignal, type JSX, type ParentProps } from 'solid-js';
+
+const DEFAULT_COL = 1 / 3;
+const DEFAULT_ROW = 0.5;
+const MIN = 0.15;
+const MAX = 0.85;
+
+function clamp(v: number): number {
+  return Math.max(MIN, Math.min(MAX, v));
+}
+
+export function ResizableGrid(props: ParentProps): JSX.Element {
+  let ref: HTMLDivElement | undefined;
+  const [col, setCol] = createSignal(DEFAULT_COL);
+  const [row, setRow] = createSignal(DEFAULT_ROW);
+  const [dragging, setDragging] = createSignal(false);
+
+  function startDrag(axis: 'col' | 'row' | 'both', e: PointerEvent) {
+    e.preventDefault();
+    const el = e.currentTarget as HTMLElement;
+    el.setPointerCapture(e.pointerId);
+    setDragging(true);
+
+    const onMove = (me: PointerEvent) => {
+      const rect = ref!.getBoundingClientRect();
+      if (axis !== 'row') setCol(clamp((me.clientX - rect.left) / rect.width));
+      if (axis !== 'col') setRow(clamp((me.clientY - rect.top) / rect.height));
+    };
+
+    const cleanup = () => {
+      el.removeEventListener('pointermove', onMove);
+      el.removeEventListener('pointerup', cleanup);
+      el.removeEventListener('lostpointercapture', cleanup);
+      setDragging(false);
+    };
+
+    el.addEventListener('pointermove', onMove);
+    el.addEventListener('pointerup', cleanup);
+    el.addEventListener('lostpointercapture', cleanup);
+  }
+
+  function reset() {
+    setCol(DEFAULT_COL);
+    setRow(DEFAULT_ROW);
+  }
+
+  return (
+    <div
+      ref={ref}
+      class="viz-grid"
+      classList={{ 'viz-grid--dragging': dragging() }}
+      style={{
+        'grid-template-columns': `${col()}fr ${1 - col()}fr`,
+        'grid-template-rows': `${row()}fr ${1 - row()}fr`,
+      }}
+    >
+      {props.children}
+
+      <div
+        class="viz-grid__handle viz-grid__handle--col"
+        style={{ left: `${col() * 100}%` }}
+        onPointerDown={(e) => startDrag('col', e)}
+        onDblClick={reset}
+      />
+      <div
+        class="viz-grid__handle viz-grid__handle--row"
+        style={{ top: `${row() * 100}%` }}
+        onPointerDown={(e) => startDrag('row', e)}
+        onDblClick={reset}
+      />
+      <div
+        class="viz-grid__handle viz-grid__handle--both"
+        style={{ left: `${col() * 100}%`, top: `${row() * 100}%` }}
+        onPointerDown={(e) => startDrag('both', e)}
+        onDblClick={reset}
+      />
+    </div>
+  );
+}

apps/cadecon/src/components/raster/RasterOverview.tsx

@@ -1,6 +1,5 @@
 import { onMount, onCleanup, createEffect, createMemo, on, type JSX } from 'solid-js';
 import { parsedData, effectiveShape, swapped } from '../../lib/data-store.ts';
-import { dataIndex } from '../../lib/data-utils.ts';
 import {
   subsetRectangles,
   selectedSubsetIdx,
@@ -132,14 +131,16 @@ export function RasterOverview(): JSX.Element {
 
     for (let py = 0; py < physH; py++) {
       const cell = Math.floor((py / physH) * N);
+      const rowBase = isSwapped ? cell : cell * rawCols;
+      const rowPixelBase = py * physW;
       for (let px = 0; px < physW; px++) {
         const t = Math.floor((px / physW) * T);
-        const v = typedData[dataIndex(cell, t, rawCols, isSwapped)];
+        const v = typedData[isSwapped ? t * rawCols + rowBase : rowBase + t];
         const normalized = Number.isFinite(v)
           ? Math.max(0, Math.min(255, Math.round(((v - p1) / range) * 255)))
           : 0;
 
-        const offset = (py * physW + px) * 4;
+        const offset = (rowPixelBase + px) * 4;
         pixels[offset] = VIRIDIS_LUT[normalized * 3];
         pixels[offset + 1] = VIRIDIS_LUT[normalized * 3 + 1];
         pixels[offset + 2] = VIRIDIS_LUT[normalized * 3 + 2];

apps/cadecon/src/lib/cadecon-pool.ts

@@ -102,15 +102,15 @@ const caDeconRouter: MessageRouter<CaDeconPoolJob, CaDeconWorkerOutbound> = {
         [job.trace.buffer],
       ];
     } else if (job.kind === 'trace') {
-      const traceCopy = new Float32Array(job.trace);
+      // warmCounts may be a .subarray() sharing a parent buffer — must copy to detach
       const warmCopy = job.warmCounts ? new Float32Array(job.warmCounts) : undefined;
-      const transfers: ArrayBuffer[] = [traceCopy.buffer];
+      const transfers: ArrayBuffer[] = [job.trace.buffer as ArrayBuffer];
       if (warmCopy) transfers.push(warmCopy.buffer);
       return [
         {
           type: 'trace-job',
           jobId: job.jobId,
-          trace: traceCopy,
+          trace: job.trace,
           tauRise: job.tauRise,
           tauDecay: job.tauDecay,
           fs: job.fs,