news digest (spec-013): rss/atom -> {news} file via cron

Replaces the broken pre-1.0-openai news_feed.py. Stdlib parsing with
defusedxml (feeds are untrusted XML), titles sanitized (SAF-03), feed
URLs SSRF-guarded. CLI: python -m fjerkroa_bot.news --config <cfg>.

tests/test_spec_news.py

@@ -0,0 +1,75 @@
+"""Unit coverage for SPEC-013 news digest (NEWS-01..03)."""
+
+import unittest
+from unittest.mock import AsyncMock
+
+from fjerkroa_bot.news import NewsFetcher, parse_feed, render_digest
+
+RSS = b"""<?xml version="1.0"?><rss><channel>
+<item><title>Game X released</title><link>https://ex.com/x</link></item>
+<item><title>Patch Y notes</title><link>https://ex.com/y</link></item>
+</channel></rss>"""
+
+ATOM = b"""<?xml version="1.0"?><feed xmlns="http://www.w3.org/2005/Atom">
+<entry><title>Atom headline</title><link href="https://ex.com/a"/></entry>
+</feed>"""
+
+
+class TestParse(unittest.TestCase):
+    def test_rss(self):
+        """NEWS-01: RSS items parsed with title + link."""
+        items = parse_feed(RSS, "Src")
+        self.assertEqual([i["title"] for i in items], ["Game X released", "Patch Y notes"])
+        self.assertEqual(items[0]["link"], "https://ex.com/x")
+        self.assertEqual(items[0]["source"], "Src")
+
+    def test_atom(self):
+        """NEWS-01: Atom entries parsed with href link."""
+        items = parse_feed(ATOM, "A")
+        self.assertEqual(items[0]["title"], "Atom headline")
+        self.assertEqual(items[0]["link"], "https://ex.com/a")
+
+    def test_malformed_never_raises(self):
+        """NEWS-01: garbage XML returns [] without raising."""
+        self.assertEqual(parse_feed(b"<not xml", "bad"), [])
+        self.assertEqual(parse_feed(b"", "empty"), [])
+
+
+class TestDigest(unittest.TestCase):
+    def test_sanitized_and_capped(self):
+        """NEWS-02: headlines sanitized, item count capped."""
+        items = [{"title": "@everyone big news \x00", "link": "", "source": "S"} for _ in range(20)]
+        digest = render_digest(items, max_items=5)
+        self.assertEqual(digest.count("\n"), 4)  # 5 lines
+        self.assertNotIn("@everyone", digest)
+        self.assertNotIn("\x00", digest)
+
+
+class TestCollect(unittest.IsolatedAsyncioTestCase):
+    async def test_ssrf_skip_and_dedup(self):
+        """NEWS-03: guarded feed skipped, dup titles dropped, bad fetch survived."""
+
+        def guard(url):
+            return "refused" if "internal" in url else None
+
+        async def fetch(url):
+            if "boom" in url:
+                raise ValueError("boom")
+            return RSS  # same content from two feeds -> dedup
+
+        fetcher = NewsFetcher(guard, fetch)
+        feeds = [
+            ("https://a.com/feed", "A"),
+            ("https://internal/feed", "Internal"),  # SSRF-skipped
+            ("https://boom.com/feed", "Boom"),  # fetch fails
+            ("https://b.com/feed", "B"),  # same RSS -> dup titles dropped
+        ]
+        items = await fetcher.collect(feeds, per_feed=5)
+        titles = [i["title"] for i in items]
+        self.assertEqual(titles, ["Game X released", "Patch Y notes"])  # deduped, internal+boom skipped
+
+    async def test_per_feed_limit(self):
+        """NEWS-03: per-feed cap honored."""
+        fetcher = NewsFetcher(lambda u: None, AsyncMock(return_value=RSS))
+        items = await fetcher.collect([("https://a.com", "A")], per_feed=1)
+        self.assertEqual(len(items), 1)