fix: import paths (fetchers→readers), schema field mismatch, RSS detection

Bugs found during fresh pip install testing:
- readers/*.py still referenced agent_eyes.fetchers → fixed to agent_eyes.readers
- reader.py passed 'author'/'metadata' to UnifiedContent which doesn't have those → use 'extra' field
- RSS URL detection missed domains containing 'rss' (e.g. hnrss.org)

agent_eyes/readers/twitter.py

@@ -15,7 +15,7 @@ import requests
 from loguru import logger
 from typing import Dict, Any
 
-from agent_eyes.fetchers.jina import fetch_via_jina
+from agent_eyes.readers.jina import fetch_via_jina
 
 
 OEMBED_URL = "https://publish.twitter.com/oembed"
@@ -75,7 +75,7 @@ async def _fetch_via_playwright(url: str) -> Dict[str, Any]:
             "  playwright install chromium"
         )
 
-    from agent_eyes.fetchers.browser import get_session_path
+    from agent_eyes.readers.browser import get_session_path
     from pathlib import Path
 
     session_path = get_session_path("twitter")