feat(queue): queue as data A2, migration, render and dispatch (#1508)

Filbert approved round 1 (f167b85e). Manifest 782bcb62, 21 files, plus
the QUEUE.md markers and the TOOLS.md section. Lead decision 35.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/queue/src/lock.mjs

@@ -129,16 +129,26 @@ export function acquire({ gitDir, io, proc = realProc, op = null, verb, waitMs =
   try {
     if (lstatOrNull(io, gate) !== null) c = classify(readOrNull(io, gate), proc);
   } catch (err) {
-    const left = release(handle, io);
+    const left = releaseOrWarn(handle, io);
     throw new QueueError(`cannot check the unlock gate ${gate}: ${errno(err)}; ${left ?? "lock released"}`, 1);
   }
   if (c !== null) {
-    release(handle, io);
-    throw new QueueError(`unlock gate ${gate} is present (${describe(c)}); check it with \`scripts/mosaic queue unlock --check-gate\``, 2);
+    const left = releaseOrWarn(handle, io);
+    throw new QueueError(`unlock gate ${gate} is present (${describe(c)}); check it with \`scripts/mosaic queue unlock --check-gate\`${left ? `\nwarning: ${left}` : ""}`, 2);
   }
   return handle;
 }
 
+// release() on a path that is already reporting something: a throw becomes
+// a message naming the lock that may be left behind (P1).
+export function releaseOrWarn(handle, io) {
+  try {
+    return release(handle, io);
+  } catch (err) {
+    return `cannot release the queue lock (${errno(err)}); ${handle.path} may be left in place`;
+  }
+}
+
 // Unlinks only the lock this process published: same inode, same record.
 export function release(handle, io) {
   const st = lstatOrNull(io, handle.path);
@@ -185,7 +195,8 @@ export function unlock({ gitDir, io, proc = realProc, hook = () => {} }) {
   // Like the lock, a swapped gate is reported on success and on refusal (8.4).
   if (msg && failure instanceof Error) failure.message += `\nwarning: ${msg}`;
   if (failure) throw failure;
-  return msg ? `${result}\nwarning: ${msg}` : result;
+  // Apart, so the caller never splits a lock record's text to find it (P3).
+  return { result, warning: msg };
 }
 
 export function checkGate({ gitDir, io, proc = realProc }) {