refactor(adapters): centralize curation in config/queries.json (issue #7)

- adapters/__init__.py: add load_queries() + source_config() (stdlib json,
  safe fallback to {} on missing/corrupt config so pipeline never crashes).
- config/queries.json: per-adapter blocks (hackernews.keywords, arxiv.categories,
  reddit.subreddits, rss.feeds+keywords, github.search_terms). JSON (not
  yaml) to honor Athena's dependency-free runtime; PyYAML avoided.
- hackernews: drop class AI_KEYWORDS + the DUPLICATE inline list inside
  _is_ai_relevant() (the internal drift Ty flagged). Now loads self.ai_keywords
  from config. Simplified matching to single substring pass (boundary variants
  'ai ',' ai','ai-','-ai' approximate word-boundary; dropped the niche
  'compute+tech-context' guard as not worth centralizing).
- reddit: DEFAULT_SUBREDDITS kept as fallback; __init__ prefers config.
- arxiv: DEFAULT_CATEGORIES kept as fallback; __init__ prefers config.
- rss: FEEDS + AI_KEYWORDS kept as module fallbacks; __init__ prefers config.
  Keywords stay regex form (re.search) as in original.
- github: trending queries moved to config search_terms; fallback retained.
- DELETE reddit_proof.py: standalone PoC v5 at repo root, own main()+init_db()
  + direct INSERT OR REPLACE, NOT in cron, NOT imported anywhere -> dead
  code. Also removes its byte-duplicate SUBREDDITS.

NOTE: fallback class constants remain intentionally (issue #7 cut #5: safe
rollout). Curation VALUES now live in one file; the constants are inert
unless config/queries.json is missing.

Verified: all adapters compile; config loads (HN 46 kw, RSS 10 feeds);
full dry-run fetches all 6 sources; grep confirms HN internal dup list gone.

adapters/rss_feeds.py

@@ -24,7 +24,7 @@ import feedparser
 from datetime import datetime, timedelta, timezone
 from email.utils import parsedate_to_datetime
 
-from adapters import SourceAdapter
+from adapters import SourceAdapter, source_config
 
 
 # Curated feed list — AI-focused, reliable, diverse publishers.
@@ -83,6 +83,18 @@ AI_KEYWORDS = [
 class RSSFeedsAdapter(SourceAdapter):
     """RSS feed aggregator for commercial AI news."""
 
+    # Module-level fallbacks (used only if config/queries.json is missing)
+    FEEDS = [
+        ("rss:techcrunch", "TechCrunch AI", "https://techcrunch.com/category/artificial-intelligence/feed/"),
+    ]
+    AI_KEYWORDS = [r"\bai\b"]
+
+    def __init__(self):
+        # Curation centralized (issue #7): config wins, fallbacks otherwise
+        cfg = source_config("rss")
+        self.feeds = cfg.get("feeds") or list(self.FEEDS)
+        self.ai_keywords = cfg.get("keywords") or list(self.AI_KEYWORDS)
+
     def name(self) -> str:
         return "rss"
 
@@ -92,7 +104,7 @@ class RSSFeedsAdapter(SourceAdapter):
         tag_text = " ".join(tags).lower()
         combined = text + " " + tag_text
 
-        for pattern in AI_KEYWORDS:
+        for pattern in self.ai_keywords:
             if re.search(pattern, combined):
                 return True
         return False
@@ -147,7 +159,7 @@ class RSSFeedsAdapter(SourceAdapter):
         all_entries = []
         feed_failures = []
 
-        for source_key, label, url in FEEDS:
+        for source_key, label, url in self.feeds:
             try:
                 d = feedparser.parse(url)
                 if d.status not in (200, 301, 302, 307, 308) or not d.entries: