Read RSS and Atom feeds, and speak about them only when asked (#258)

internal/rss parses RSS 2.0 and Atom, and polls each configured feed on its own
interval; internal/webfetch is the one door either of them uses to touch the
network. The poller writes items as notes with source "rss:<feed>" and nothing
else: the answer path reads them back when he asks "что нового в лентах?", and
nothing is announced on arrival. A feed that dispatched would be a nag, which is
why the plan's breaking-news rule was left out rather than built.

webfetch is where the limits live, as code rather than a paragraph: http(s)
only, an allowlist (the configured feeds' hosts) and a denylist, a 2 MiB body
cap, a 3-redirect cap, one request per host per second, and a refusal to connect
to any private address — checked in the dialer's Control hook so it holds for
every resolved address and every redirect hop, not just for a literal IP.

Off unless configured: no "feeds" block, no poller, no outbound request. How far
a feed was read is a config fact (rss:latest:<name>), so a restart does not
re-note yesterday's headlines.

docs/plans/13-rss-news-feeds.md

@@ -27,3 +27,28 @@
 7. Add voice query handler — `"что нового?"` queries `RecentNotes` filtered by source prefix `rss:` and phrases via `phraser.PhraseQuery`
 8. Add `feeds` block to `config.Config` and `deploy/mavend.json`
 9. Test with a live RSS feed (e.g., `https://news.ycombinator.com/rss`) — verify items appear in notes table
+
+---
+
+## Shipped 2026-08-01 (#258)
+
+`internal/webfetch` (the guarded HTTP door: scheme, allow/deny hosts, private-address
+refusal in the dialer, size cap, redirect cap, per-host rate limit), `internal/rss`
+(RSS 2.0 + Atom parser, poller with durable marks and a keyword filter),
+`cmd/mavend/feeds.go` (ticker, fetcher adapter, `rss:latest:<feed>` fact marks),
+config block `feeds`, and the `feeds` query source with `router.ParseFeedQuery`.
+
+Deviations from the plan above, both deliberate:
+
+- **Step 5 (breaking-news nudges) was not built.** A feed that dispatches is a nag,
+  and the one thing Maven is not is a nag. Items are read when asked and nowhere else.
+  If breaking news is ever wanted, it belongs behind the existing delivery policy
+  (severity, quiet hours, digest), not in the poller.
+- **Step 3 (embedder relevance) is a seam, not an implementation.** `rss.Ranker`
+  exists and is wired nil. Scoring items against an "interest profile" needs a
+  profile, and there is none yet; a threshold with nothing to compare against is a
+  random filter with a confident name. The filter that runs is the per-feed
+  include/exclude keyword list, which he can read and predict.
+
+No new dependency: stdlib `encoding/xml`, no gofeed. Stock deploy config has no
+`feeds` block, so the capability is off.