feat: file_name combo on ProjectSource, sequence_number output

- file_name is now a combo dropdown populated from the API when
  manager_url and project_name are set
- ProjectSource outputs sequence_number (INT) for downstream use
- Refreshes file list when project_name or manager_url changes
- Updated tests for new output and error-default behavior

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/project_source.js

@@ -1,4 +1,5 @@
 import { app } from "../../scripts/app.js";
+import { api } from "../../scripts/api.js";
 
 app.registerExtension({
     name: "json.manager.project.source",
@@ -6,6 +7,56 @@ app.registerExtension({
     async beforeRegisterNodeDef(nodeType, nodeData, app) {
         if (nodeData.name !== "ProjectSource") return;
 
+        // Helper: replace a STRING widget with a proper combo widget
+        function replaceWithCombo(node, name, values, callback) {
+            const idx = node.widgets?.findIndex(w => w.name === name);
+            if (idx === -1 || idx === undefined) return null;
+            const oldWidget = node.widgets[idx];
+            const savedValue = oldWidget.value || "";
+            const comboValues = values.length > 0 ? values : [""];
+            // Always preserve saved value (may not be in list yet)
+            if (savedValue && !comboValues.includes(savedValue)) {
+                comboValues.unshift(savedValue);
+            }
+            const defaultValue = savedValue || comboValues[0];
+            node.widgets.splice(idx, 1);
+            const combo = node.addWidget("combo", name, defaultValue, callback, { values: comboValues });
+            if (node.widgets.length > 1) {
+                node.widgets.splice(node.widgets.length - 1, 1);
+                node.widgets.splice(idx, 0, combo);
+            }
+            return combo;
+        }
+
+        // Fetch file list from API and update file_name combo
+        async function refreshFiles(node) {
+            const urlW = node.widgets?.find(w => w.name === "manager_url");
+            const projW = node.widgets?.find(w => w.name === "project_name");
+            if (!urlW?.value || !projW?.value) return;
+
+            try {
+                const resp = await api.fetchApi(
+                    `/json_manager/list_project_files?url=${encodeURIComponent(urlW.value)}&project=${encodeURIComponent(projW.value)}`
+                );
+                if (!resp.ok) return;
+                const data = await resp.json();
+                if (!Array.isArray(data)) return;
+
+                const fileW = node.widgets?.find(w => w.name === "file_name");
+                if (fileW) {
+                    const currentValue = fileW.value;
+                    fileW.options.values = data.length > 0 ? data : [""];
+                    // Keep current selection if still valid
+                    if (currentValue && data.includes(currentValue)) {
+                        fileW.value = currentValue;
+                    }
+                    console.log(`[ProjectSource] refreshFiles: ${data.length} files loaded`);
+                }
+            } catch (e) {
+                console.error("[ProjectSource] Failed to refresh files:", e);
+            }
+        }
+
         // Notify all ProjectKey nodes referencing this source to re-sync
         function notifyRelays(sourceNode) {
             if (!sourceNode.graph?._nodes) return;
@@ -33,18 +84,34 @@ app.registerExtension({
 
             const node = this;
 
-            // Hook all config widgets to notify relays on change
-            for (const name of ["manager_url", "project_name", "file_name", "sequence_number"]) {
+            // Replace file_name STRING with a combo
+            replaceWithCombo(this, "file_name", [], function (value) {
+                notifyRelays(node);
+            });
+
+            // Hook manager_url and project_name to refresh file list + notify relays
+            for (const name of ["manager_url", "project_name"]) {
                 const w = this.widgets?.find(w => w.name === name);
                 if (w) {
                     const origCb = w.callback;
                     w.callback = function (...args) {
                         origCb?.apply(this, args);
+                        refreshFiles(node);
                         notifyRelays(node);
                     };
                 }
             }
 
+            // Hook sequence_number to notify relays
+            const seqW = this.widgets?.find(w => w.name === "sequence_number");
+            if (seqW) {
+                const origCb = seqW.callback;
+                seqW.callback = function (...args) {
+                    origCb?.apply(this, args);
+                    notifyRelays(node);
+                };
+            }
+
             // Update title when label changes
             const labelWidget = this.widgets?.find(w => w.name === "label");
             if (labelWidget) {
@@ -66,10 +133,26 @@ app.registerExtension({
         const origOnConfigure = nodeType.prototype.onConfigure;
         nodeType.prototype.onConfigure = function (info) {
             origOnConfigure?.apply(this, arguments);
+
+            // Ensure file_name is a combo (may be STRING from serialization)
+            const fileW = this.widgets?.find(w => w.name === "file_name");
+            if (fileW && fileW.type !== "combo") {
+                const node = this;
+                replaceWithCombo(this, "file_name", [], function (value) {
+                    notifyRelays(node);
+                });
+            }
+
             const labelWidget = this.widgets?.find(w => w.name === "label");
             if (labelWidget?.value) {
                 this.title = `Source: ${labelWidget.value}`;
             }
+
+            // Deferred: refresh file list once graph is ready
+            const node = this;
+            queueMicrotask(() => {
+                refreshFiles(node);
+            });
         };
     },
 });