News post → town crier + Discord announcement pipeline

Replace the fire-and-forget Discord-only announce on publish with a
retry-safe, two-leg pipeline. When a post transitions into published-news
(false→true publish while in news, or category→news while published), an
announce_jobs row is enqueued with two INDEPENDENT delivery legs:

  • town crier — sidecar POST /towncrier via uoLinkClient (stable id
    `post-<id>` so a retry replaces rather than duplicates)
  • discord    — bot POST /internal/announce via botInternalClient
    (single source of truth for the #news channel stays in the bot)

An in-process poller (utils/announceWorker) sweeps the table every
ANNOUNCE_POLL_MS and dispatches each due leg with its own exponential
backoff (30s→2h, 6 attempts). A leg is retried on transient failures
(503/504/network) and failed fast on data/config errors (400 over-cap,
401/409). Publishing never blocks on the sidecar or Discord — enqueue is
local DB only. Parent `status` is a done/partial/failed rollup of the two
legs; posts.announced_at is stamped once both deliver.

Admin visibility: GET /admin/posts/:id/announce + a per-leg Retry
(POST .../announce/retry) surfaced in the PostEditor for news posts.

Pure decisions (text build/caps, classification, backoff, rollup) live in
announceJobs.logic and are unit-tested (server/test/announceJobs.test.js,
10 tests). The old manual /admin/uo-link/towncrier form is untouched.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0114TpmrNW4wNXsHq5CR72jQ

server/src/model/posts/posts.model.js

@@ -78,6 +78,15 @@ async function setPublished(id, published) {
   return postsDb.findById(id)
 }
 
+// Announcement pipeline back-pointers (see model/announceJobs).
+async function linkAnnounceJob(id, jobId) {
+  await postsDb.update(id, { announce_job_id: jobId })
+}
+
+async function markAnnounced(id, at = new Date()) {
+  await postsDb.update(id, { announced_at: at })
+}
+
 async function remove(id) {
   return postsDb.remove(id)
 }
@@ -103,6 +112,8 @@ module.exports = {
   create,
   update,
   setPublished,
+  linkAnnounceJob,
+  markAnnounced,
   remove,
   counts,
 }