Address review feedback: deduplicate query_type, clean unused imports, fix defaults

- Remove duplicate detect_query_type from query.py (divergent 5-type version);
  canonical 7-type version lives in query_type.py
- Fix reddit.py import to use query_type.detect_query_type
- Clean unused STOPWORDS/SYNONYMS/tokenize imports from youtube_yt, instagram,
  tiktok, scrapecreators_x, bird_x after relevance consolidation
- Fix _relevance_filter default from 0.7 to 0.0 (items without relevance
  should not silently pass the filter)
- Remove --dateafter from yt-dlp (returns 0 results for evergreen topics)
- Remove restrictSearchableAttributes from HN search (misses Ask/Show HN)
- Lower HN points filter from >5 to >2 (avoids filtering niche posts)
- Add error logging to select_openai_model HTTP failures
- Remove mise.toml and internal planning doc from repo
- Update module docstrings to describe current purpose, not migration history
- Update tests to import from canonical relevance module

tests/test_query.py

@@ -6,7 +6,7 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "scripts"))
 
-from lib.query import NOISE_WORDS, detect_query_type, extract_compound_terms, extract_core_subject
+from lib.query import NOISE_WORDS, extract_compound_terms, extract_core_subject
 
 
 class TestExtractCoreSubject(unittest.TestCase):
@@ -126,27 +126,6 @@ class TestNoiseWordsCompleteness(unittest.TestCase):
             self.assertIn(w, NOISE_WORDS)
 
 
-class TestDetectQueryType(unittest.TestCase):
-    """Tests for detect_query_type()."""
-
-    def test_comparison(self):
-        self.assertEqual(detect_query_type("React vs Vue"), "comparison")
-
-    def test_how_to(self):
-        self.assertEqual(detect_query_type("how to deploy on Vercel"), "how_to")
-
-    def test_opinion(self):
-        self.assertEqual(detect_query_type("cursor IDE worth it"), "opinion")
-
-    def test_product(self):
-        self.assertEqual(detect_query_type("cursor IDE pricing"), "product")
-
-    def test_concept_default(self):
-        self.assertEqual(detect_query_type("multi-agent reinforcement learning"), "concept")
-
-    def test_how_prefix(self):
-        self.assertEqual(detect_query_type("how does Claude work"), "how_to")
-
 
 class TestExtractCompoundTerms(unittest.TestCase):
     """Tests for extract_compound_terms()."""