exporter: convert NOT_CHANGED_SINCE epoch to ISO on passthrough; set to now on re-serialize

static/exporter.js

@@ -112,11 +112,24 @@ function _instrCharacterLines(instr) {
     });
 }
 
+// RFC §4.4.1: DATE = YYYY-MM-DD HH:MM:SS
+// notChangedSince from AST log is a float epoch; score YAML must have ISO date.
+
+function _epochToISO(val) {
+    if (!val) return null;
+    if (typeof val === 'string') return val;
+    return new Date(val * 1000).toISOString().slice(0, 19).replace('T', ' ');
+}
+
+function _nowISO() {
+    return new Date().toISOString().slice(0, 19).replace('T', ' ');
+}
+
 // RFC §4.4: embedded instrument key is "instrument NAME:" not "instrument: 'NAME'"
 
 export function exportInstrument(instr) {
     const lines = [`instrument ${instr.name}:`];
-    if (instr.notChangedSince) lines.push(`  NOT_CHANGED_SINCE: ${instr.notChangedSince}`);
+    lines.push(`  NOT_CHANGED_SINCE: ${_nowISO()}`);
     lines.push(`  character:`);
     lines.push(..._instrCharacterLines(instr));
     return lines.join('\n');
@@ -210,6 +223,13 @@ function _patchInstrumentHeader(text, instruments) {
             } else if (instr.isLinked && !instr._modified) {
                 result.push(line);
                 i++;
+                while (i < lines.length && (lines[i].startsWith(' ') || lines[i] === '')) {
+                    if (/^\s+NOT_CHANGED_SINCE\s*:/.test(lines[i]))
+                        result.push(`  NOT_CHANGED_SINCE: ${_epochToISO(instr.notChangedSince)}`);
+                    else
+                        result.push(lines[i]);
+                    i++;
+                }
             } else {
                 i++;
                 while (i < lines.length && (lines[i].startsWith(' ') || lines[i] === '')) i++;