issue-lifecycle: greet new unmilestoned issues with a comment

When an issue is opened without a milestone, post a friendly comment
alongside the not-approved label so the reporter knows it's queued for
triage. Scoped to the opened event only to avoid spamming old issues on
cron reconciliation.

scripts/issue-lifecycle/config.ts

@@ -51,6 +51,11 @@ This isn't a judgment of the issue's merit — just routine triage. @${author},
 
 — *Automated.*`,
 
+  NEW_ISSUE_NOT_APPROVED: (author: string): string =>
+    `Hi @${author}, thanks for opening this issue. It hasn't been approved by a maintainer yet — we'll get back to you shortly to either milestone it (approval) or close it.
+
+— *Automated. See [CONTRIBUTING.md](https://github.com/${REPO.owner}/${REPO.repo}/blob/main/CONTRIBUTING.md).*`,
+
   UNASSIGNED_NO_MILESTONE: (assignees: string[]): string =>
     `${assignees.map((u) => "@" + u).join(", ")} — you've been unassigned from this issue automatically because it doesn't have a milestone set.
 

scripts/issue-lifecycle/events.ts

@@ -1,4 +1,5 @@
 import type { Octokit } from "@octokit/rest";
+import { COMMENTS } from "./config";
 import { type Action, applyActions, describeAction, getIssue } from "./github";
 import { syncApprovalLabel } from "./rules/approval-label-sync";
 import { enforceAssignmentInvariant } from "./rules/assignment-invariant";
@@ -55,6 +56,18 @@ export async function runEvent(
     });
   }
 
+  if (eventName === "opened" && issue.milestone === null) {
+    buckets.push({
+      rule: "new-issue-greeting",
+      actions: [
+        {
+          type: "comment",
+          body: COMMENTS.NEW_ISSUE_NOT_APPROVED(issue.user?.login ?? "there"),
+        },
+      ],
+    });
+  }
+
   let acted = false;
   for (const { rule, actions } of buckets) {
     if (actions.length === 0) continue;