Add destructive-action confirmations in inspector editors

frontend/app.js

@@ -1701,6 +1701,51 @@ function hasNodeOnNet(net, ref, pin) {
   return (net.nodes ?? []).some((n) => n.ref === ref && n.pin === pin);
 }
 
+function refsForSymbol(symbolId) {
+  return new Set((state.model?.instances ?? []).filter((i) => i.symbol === symbolId).map((i) => i.ref));
+}
+
+function symbolPinUsage(symbolId, pinName) {
+  const refs = refsForSymbol(symbolId);
+  const nets = new Set();
+  let nodes = 0;
+  for (const net of state.model?.nets ?? []) {
+    for (const node of net.nodes ?? []) {
+      if (refs.has(node.ref) && node.pin === pinName) {
+        nodes += 1;
+        nets.add(net.name);
+      }
+    }
+  }
+  return { refs: refs.size, nodes, nets: [...nets].sort() };
+}
+
+function disconnectImpact(netName, ref, pin) {
+  const net = netByName(netName);
+  if (!net) {
+    return { remainingNodes: 0, orphaned: false };
+  }
+  const remainingNodes = (net.nodes ?? []).filter((n) => !(n.ref === ref && n.pin === pin)).length;
+  return {
+    remainingNodes,
+    orphaned: remainingNodes < 2
+  };
+}
+
+function deleteComponentImpact(ref) {
+  const impacted = [];
+  let removedNodes = 0;
+  for (const net of state.model?.nets ?? []) {
+    const before = net.nodes?.length ?? 0;
+    const after = (net.nodes ?? []).filter((n) => n.ref !== ref).length;
+    if (before !== after) {
+      removedNodes += before - after;
+      impacted.push({ name: net.name, removed: before - after, orphaned: after < 2 });
+    }
+  }
+  return { removedNodes, impacted };
+}
+
 function connectPinToNet(ref, pin, netName, opts = {}) {
   if (!state.model) {
     return { ok: false, message: "No model loaded." };
@@ -2283,6 +2328,16 @@ function setupEvents() {
       return;
     }
     const ref = state.selectedRef;
+    const impact = deleteComponentImpact(ref);
+    const orphaned = impact.impacted.filter((x) => x.orphaned).map((x) => x.name);
+    const summary =
+      `Delete ${ref}?\n` +
+      `- Net nodes removed: ${impact.removedNodes}\n` +
+      `- Nets touched: ${impact.impacted.length}\n` +
+      (orphaned.length ? `- Nets that will be removed (<2 nodes): ${orphaned.slice(0, 8).join(", ")}${orphaned.length > 8 ? " ..." : ""}\n` : "");
+    if (!window.confirm(summary)) {
+      return;
+    }
     pushHistory("delete-component");
     state.model.instances = state.model.instances.filter((i) => i.ref !== ref);
     for (const net of state.model.nets ?? []) {
@@ -2416,6 +2471,13 @@ function setupEvents() {
       return;
     }
     const netName = btn.getAttribute("data-disconnect-net");
+    const impact = disconnectImpact(netName, state.selectedPin.ref, state.selectedPin.pin);
+    const message = impact.orphaned
+      ? `Disconnect ${state.selectedPin.ref}.${state.selectedPin.pin} from ${netName}?\nThis will leave fewer than 2 nodes and remove net '${netName}'.`
+      : `Disconnect ${state.selectedPin.ref}.${state.selectedPin.pin} from ${netName}?`;
+    if (!window.confirm(message)) {
+      return;
+    }
     pushHistory("disconnect-pin");
     const out = disconnectPinFromNet(state.selectedPin.ref, state.selectedPin.pin, netName);
     if (!out.ok) {
@@ -2487,6 +2549,13 @@ function setupEvents() {
     const netName = state.selectedNet;
     const [ref, ...pinParts] = String(btn.getAttribute("data-remove-node")).split(".");
     const pin = pinParts.join(".");
+    const impact = disconnectImpact(netName, ref, pin);
+    const message = impact.orphaned
+      ? `Remove ${ref}.${pin} from ${netName}?\nThis will leave fewer than 2 nodes and remove net '${netName}'.`
+      : `Remove ${ref}.${pin} from ${netName}?`;
+    if (!window.confirm(message)) {
+      return;
+    }
     pushHistory("net-node-remove");
     const out = disconnectPinFromNet(ref, pin, netName);
     if (!out.ok) {
@@ -2532,6 +2601,22 @@ function setupEvents() {
     }
     const row = btn.closest(".symbolPinRow");
     if (row) {
+      const pinName = String(row.querySelector(".pinName")?.value ?? row.getAttribute("data-old-pin") ?? "").trim();
+      const inst = state.selectedRef ? instanceByRef(state.selectedRef) : null;
+      if (inst && pinName) {
+        const usage = symbolPinUsage(inst.symbol, pinName);
+        if (usage.nodes > 0) {
+          const netSample = usage.nets.slice(0, 8).join(", ");
+          const suffix = usage.nets.length > 8 ? " ..." : "";
+          const prompt =
+            `Remove pin row '${pinName}' from symbol '${inst.symbol}' editor?\n` +
+            `Current usage: ${usage.nodes} net node(s) across ${usage.nets.length} net(s): ${netSample}${suffix}\n` +
+            "These references will be dropped when you apply symbol changes.";
+          if (!window.confirm(prompt)) {
+            return;
+          }
+        }
+      }
       row.remove();
       invalidateSymbolMigrationPreview("Pin rows changed. Preview migration again before apply.");
     }