feat: Binance WS, news client, and social client

Add ThreadedWebsocketManager-based BinanceWSClient for real-time price
streaming, NewsClient for CryptoPanic/NewsAPI fetching with coin filtering,
and SocialClient for Reddit post retrieval with keyword filtering and
simple keyword-based sentiment scoring. Includes unit tests for news and
social clients (4/4 passing).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

data/news_client.py

@@ -0,0 +1,73 @@
+import httpx
+import logging
+from datetime import datetime, timedelta, timezone
+
+logger = logging.getLogger(__name__)
+
+class NewsClient:
+    CRYPTOPANIC_URL = "https://cryptopanic.com/api/free/v1/posts/"
+    NEWSAPI_URL = "https://newsapi.org/v2/everything"
+
+    def __init__(self, cryptopanic_key: str, newsapi_key: str = ""):
+        self.cryptopanic_key = cryptopanic_key
+        self.newsapi_key = newsapi_key
+        self._cache: list[dict] = []
+        self._cache_time: datetime | None = None
+
+    def fetch_cryptopanic(self) -> list[dict]:
+        try:
+            resp = httpx.get(
+                self.CRYPTOPANIC_URL,
+                params={"auth_token": self.cryptopanic_key, "filter": "hot", "public": "true"},
+                timeout=10,
+            )
+            resp.raise_for_status()
+            return self.parse_cryptopanic(resp.json())
+        except Exception as e:
+            logger.warning(f"CryptoPanic fetch failed: {e}")
+            return self._cache
+
+    def parse_cryptopanic(self, raw: dict) -> list[dict]:
+        articles = []
+        for item in raw.get("results", []):
+            currencies = item.get("currencies") or []
+            for cur in currencies:
+                articles.append({
+                    "coin": cur.get("code", ""),
+                    "title": item.get("title", ""),
+                    "published_at": item.get("published_at", ""),
+                    "kind": item.get("kind", "news"),
+                    "sentiment_votes": item.get("votes", {}),
+                })
+        return articles
+
+    def fetch_newsapi(self, query: str = "cryptocurrency") -> list[dict]:
+        if not self.newsapi_key:
+            return []
+        try:
+            since = (datetime.now(timezone.utc) - timedelta(days=1)).strftime("%Y-%m-%d")
+            resp = httpx.get(
+                self.NEWSAPI_URL,
+                params={"q": query, "from": since, "sortBy": "publishedAt",
+                        "apiKey": self.newsapi_key, "language": "en", "pageSize": 50},
+                timeout=10,
+            )
+            resp.raise_for_status()
+            return [
+                {"coin": "", "title": a["title"], "published_at": a["publishedAt"],
+                 "kind": "news", "sentiment_votes": {}}
+                for a in resp.json().get("articles", [])
+            ]
+        except Exception as e:
+            logger.warning(f"NewsAPI fetch failed: {e}")
+            return []
+
+    def fetch_all(self) -> list[dict]:
+        articles = self.fetch_cryptopanic() + self.fetch_newsapi()
+        self._cache = articles
+        self._cache_time = datetime.now(timezone.utc)
+        return articles
+
+    def filter_by_coin(self, articles: list[dict], coin_symbol: str) -> list[dict]:
+        symbol = coin_symbol.replace("USDT", "")
+        return [a for a in articles if a["coin"].upper() == symbol.upper()]