news webhook posting mode: replaces py3.8 getnews (bounded state, seed-on-first-run, ssrf-guarded)

specs/SPEC-013-news.md

@@ -23,3 +23,32 @@ or control characters into the prompt via a headline.
 `NewsFetcher.collect` skips any feed URL the SSRF guard rejects,
 skips feeds that fail to fetch (one bad feed never sinks the run),
 and drops duplicate headlines across feeds.
+
+## Webhook posting (ggg model)
+
+`--post` mode fetches feeds mapped to channels and posts NEW items to
+the channel's Discord webhook — replacing the py3.8 `getnews.py`
+(dead play3 feed, 35 MB substring-scan state file, HTML-redirect
+cruft). Config: `news-post-feeds = [[url, label, channel], …]`,
+`news-post-webhooks = {channel = url}`, `news-post-state`.
+
+### NEWS-04 — Only unseen items post, then are marked seen (coverage: test)
+
+`NewsPoster.run_post` posts each item whose key (link, else title) is
+not in the seen-set, adds it to the set, and posts to the mapped
+channel's webhook. Re-runs over the same feed post nothing new.
+
+### NEWS-05 — First run seeds without flooding (coverage: test)
+
+With no prior state file (`seed_only`), every current item is marked
+seen but nothing is posted — migrating off getnews.py never dumps a
+backlog into the channels. `news-post-max-per-run` caps steady-state
+posts per run.
+
+### NEWS-06 — Post failures and bad channels are survived (coverage: test)
+
+A feed the SSRF guard rejects, a feed that fails to fetch, an item
+whose channel has no configured webhook, and a webhook POST that
+raises are each logged and skipped — one failure never sinks the
+run, and the seen-set still advances for successfully-processed
+items.