feat: write subagent dispatch receipt state

scripts/subagent_delivery_watchdog.mjs

@@ -1,8 +1,12 @@
 #!/usr/bin/env node
 
 import fs from 'node:fs';
+import path from 'node:path';
 import process from 'node:process';
 
+const ROOT_DIR = path.resolve(import.meta.dirname, '..');
+const STATE_DIR = path.join(ROOT_DIR, 'state', 'subagent-delivery-watchdog');
+
 function parseArgs(argv) {
   const args = {
     compact: false,
@@ -44,7 +48,9 @@ function printHelp() {
     '',
     'Minimal CLI skeleton for the subagent delivery watchdog.',
   ];
-  process.stdout.write(`${lines.join('\n')}\n`);
+  process.stdout.write(`${lines.join('
+')}
+`);
 }
 
 function tryReadInput(inputPath) {
@@ -64,6 +70,7 @@ function tryReadInput(inputPath) {
       exists: true,
       bytes: Buffer.byteLength(content, 'utf8'),
       preview: content.slice(0, 200),
+      content,
     };
   } catch (error) {
     return {
@@ -76,6 +83,48 @@ function tryReadInput(inputPath) {
   }
 }
 
+function tryParseJson(content) {
+  if (typeof content !== 'string' || content.length === 0) {
+    return null;
+  }
+
+  try {
+    return JSON.parse(content);
+  } catch {
+    return null;
+  }
+}
+
+function writeDispatchReceiptState(payload) {
+  if (!payload || typeof payload !== 'object') {
+    return null;
+  }
+
+  const { runId, childSessionKey, dispatchAt, expectedBy } = payload;
+
+  if (![runId, childSessionKey, dispatchAt, expectedBy].every((value) => typeof value === 'string' && value.length > 0)) {
+    return null;
+  }
+
+  fs.mkdirSync(STATE_DIR, { recursive: true });
+
+  const statePath = path.join(STATE_DIR, `${runId}.json`);
+  const dispatchRecord = {
+    runId,
+    childSessionKey,
+    dispatchAt,
+    expectedBy,
+  };
+
+  fs.writeFileSync(statePath, `${JSON.stringify(dispatchRecord, null, 2)}
+`, 'utf8');
+
+  return {
+    statePath,
+    record: dispatchRecord,
+  };
+}
+
 function main() {
   const args = parseArgs(process.argv.slice(2));
 
@@ -85,11 +134,18 @@ function main() {
   }
 
   const input = tryReadInput(args.input);
+  const inputPayload = input.exists ? tryParseJson(input.content) : null;
+  const dispatchWrite = writeDispatchReceiptState(inputPayload);
+
+  if ('content' in input) {
+    delete input.content;
+  }
+
   const response = {
     ok: true,
     tool: 'subagent_delivery_watchdog',
-    version: 'skeleton-v1',
-    mode: 'placeholder',
+    version: 'skeleton-v2',
+    mode: 'dispatch-receipt-write',
     args: {
       compact: args.compact,
       input: args.input,
@@ -97,13 +153,15 @@ function main() {
     input,
     result: {
       status: 'not_implemented',
-      message: 'Watchdog skeleton ready for follow-up tasks.',
-      records: [],
+      message: 'Dispatch receipt write is implemented; status recompute remains pending.',
+      records: dispatchWrite ? [dispatchWrite.record] : [],
+      dispatchReceiptWrite: dispatchWrite,
     },
   };
 
   const spacing = args.compact ? 0 : 2;
-  process.stdout.write(`${JSON.stringify(response, null, spacing)}\n`);
+  process.stdout.write(`${JSON.stringify(response, null, spacing)}
+`);
 }
 
 main();