fix(chart): restore realtime updates and axes

web/js/app.js

@@ -14,6 +14,7 @@ import {
 import { startLogs, startPointSocket } from "./logs.js";
 import {
   clearBatchBinding,
+  browseAndLoadTree,
   clearSelectedPoints,
   createPoints,
   loadPoints,
@@ -47,7 +48,7 @@ function bindEvents() {
     dom.nodeTree.innerHTML = '<div class="muted">Click "Load Nodes" to fetch node tree</div>';
     dom.pointSourceNodeCount.textContent = "Nodes: 0";
   });
-  dom.browseNodesBtn.addEventListener("click", () => withStatus(loadTree()));
+  dom.browseNodesBtn.addEventListener("click", () => withStatus(browseAndLoadTree()));
   dom.refreshTreeBtn.addEventListener("click", () => withStatus(loadTree()));
   dom.createPointsBtn.addEventListener("click", () => withStatus(createPoints()));
   dom.closeModalBtn.addEventListener("click", () => dom.pointModal.classList.add("hidden"));

web/js/chart.js

@@ -3,13 +3,53 @@ import { dom } from "./dom.js";
 import { state } from "./state.js";
 
 function normalizeChartItem(item) {
+  let valueNumber = null;
+  if (typeof item?.value_number === "number" && Number.isFinite(item.value_number)) {
+    valueNumber = item.value_number;
+  } else if (typeof item?.value === "number" && Number.isFinite(item.value)) {
+    valueNumber = item.value;
+  } else if (typeof item?.value === "boolean") {
+    valueNumber = item.value ? 1 : 0;
+  } else if (typeof item?.value?.float === "number" && Number.isFinite(item.value.float)) {
+    valueNumber = item.value.float;
+  } else if (typeof item?.value?.int === "number" && Number.isFinite(item.value.int)) {
+    valueNumber = item.value.int;
+  } else if (typeof item?.value?.uint === "number" && Number.isFinite(item.value.uint)) {
+    valueNumber = item.value.uint;
+  } else if (typeof item?.value?.bool === "boolean") {
+    valueNumber = item.value.bool ? 1 : 0;
+  } else if (typeof item?.value_text === "string") {
+    const parsed = Number(item.value_text);
+    if (Number.isFinite(parsed)) {
+      valueNumber = parsed;
+    }
+  }
+
   return {
     timestamp: item?.timestamp || "",
-    valueNumber: typeof item?.value_number === "number" ? item.value_number : null,
+    valueNumber,
-    valueText: item?.value_text || "",
+    valueText: item?.value_text || (valueNumber === null ? "" : String(valueNumber)),
   };
 }
 
+function formatAxisValue(value) {
+  if (!Number.isFinite(value)) {
+    return "--";
+  }
+  if (Math.abs(value) >= 1000 || Math.abs(value) < 0.01) {
+    return value.toExponential(2);
+  }
+  return value.toFixed(2);
+}
+
+function formatTimeLabel(timestamp) {
+  if (!timestamp) {
+    return "--";
+  }
+  const match = String(timestamp).match(/(\d{2}:\d{2}:\d{2})/);
+  return match ? match[1] : String(timestamp);
+}
+
 export async function openChart(pointId, pointName) {
   state.chartPointId = pointId;
   state.chartPointName = pointName || "Point";
@@ -72,10 +112,56 @@ export function renderChart() {
     max += 1;
   }
 
-  const padding = { top: 20, right: 20, bottom: 36, left: 52 };
+  const padding = { top: 20, right: 20, bottom: 42, left: 64 };
   const plotWidth = width - padding.left - padding.right;
   const plotHeight = height - padding.top - padding.bottom;
 
+  ctx.strokeStyle = "#cbd5e1";
+  ctx.lineWidth = 1;
+
+  for (let i = 0; i <= 4; i += 1) {
+    const y = padding.top + (plotHeight / 4) * i;
+    ctx.beginPath();
+    ctx.moveTo(padding.left, y);
+    ctx.lineTo(width - padding.right, y);
+    ctx.stroke();
+  }
+
+  ctx.beginPath();
+  ctx.moveTo(padding.left, padding.top);
+  ctx.lineTo(padding.left, height - padding.bottom);
+  ctx.lineTo(width - padding.right, height - padding.bottom);
+  ctx.strokeStyle = "#94a3b8";
+  ctx.stroke();
+
+  ctx.fillStyle = "#64748b";
+  ctx.font = "12px Segoe UI";
+  for (let i = 0; i <= 4; i += 1) {
+    const value = max - ((max - min) / 4) * i;
+    const y = padding.top + (plotHeight / 4) * i;
+    ctx.fillText(formatAxisValue(value), 8, y + 4);
+  }
+
+  const firstLabel = formatTimeLabel(state.chartData[0]?.timestamp);
+  const middleLabel = formatTimeLabel(
+    state.chartData[Math.floor((state.chartData.length - 1) / 2)]?.timestamp,
+  );
+  const lastLabel = formatTimeLabel(state.chartData[state.chartData.length - 1]?.timestamp);
+
+  ctx.fillText(firstLabel, padding.left, height - 12);
+  const middleWidth = ctx.measureText(middleLabel).width;
+  ctx.fillText(middleLabel, padding.left + plotWidth / 2 - middleWidth / 2, height - 12);
+  const lastWidth = ctx.measureText(lastLabel).width;
+  ctx.fillText(lastLabel, width - padding.right - lastWidth, height - 12);
+
+  ctx.save();
+  ctx.translate(16, padding.top + plotHeight / 2);
+  ctx.rotate(-Math.PI / 2);
+  ctx.fillStyle = "#64748b";
+  ctx.fillText("Value", 0, 0);
+  ctx.restore();
+  ctx.fillText("Time", width / 2 - 12, height - 28);
+
   ctx.strokeStyle = "#2563eb";
   ctx.lineWidth = 2;
   ctx.beginPath();

web/js/points.js

@@ -123,6 +123,17 @@ export async function loadTree() {
   updatePointSourceNodeCount();
 }
 
+export async function browseAndLoadTree() {
+  const sourceId = dom.pointSourceSelect.value || state.selectedSourceId;
+  if (!sourceId) {
+    throw new Error("Select a source first");
+  }
+
+  state.selectedSourceId = sourceId;
+  await apiFetch(`/api/source/${sourceId}/browse`, { method: "POST" });
+  await loadTree();
+}
+
 export async function createPoints() {
   if (!state.selectedNodeIds.size) {
     return;