Tags and site names improvements (#2427)

- Added social tag to social networks (33 sites)
- Fixed wrong tags (8 sites)
- Filled empty tags for 213 sites in top-1000
- Country tag cleanup (~374 sites)
- Site naming normalization (75 sites)
- New tests (3)
- Documentation updates

tests/test_data.py

@@ -4,6 +4,30 @@ import pytest
 from maigret.utils import is_country_tag
 
 
+TOP_SITES_ALEXA_RANK_LIMIT = 50
+
+KNOWN_SOCIAL_DOMAINS = [
+    "facebook.com",
+    "instagram.com",
+    "twitter.com",
+    "tiktok.com",
+    "vk.com",
+    "reddit.com",
+    "pinterest.com",
+    "snapchat.com",
+    "linkedin.com",
+    "tumblr.com",
+    "threads.net",
+    "bsky.app",
+    "myspace.com",
+    "weibo.com",
+    "mastodon.social",
+    "gab.com",
+    "minds.com",
+    "clubhouse.com",
+]
+
+
 @pytest.mark.slow
 def test_tags_validity(default_db):
     unknown_tags = set()
@@ -19,3 +43,62 @@ def test_tags_validity(default_db):
     # if you see "unchecked" tag error, please, do
     # maigret --db `pwd`/maigret/resources/data.json --self-check --tag unchecked --use-disabled-sites
     assert unknown_tags == set()
+
+
+@pytest.mark.slow
+def test_top_sites_have_category_tag(default_db):
+    """Top sites by alexaRank must have at least one category tag (not just country codes)."""
+    sites_ranked = sorted(
+        [s for s in default_db.sites if s.alexa_rank],
+        key=lambda s: s.alexa_rank,
+    )[:TOP_SITES_ALEXA_RANK_LIMIT]
+
+    missing_category = []
+    for site in sites_ranked:
+        category_tags = [t for t in site.tags if not is_country_tag(t)]
+        if not category_tags:
+            missing_category.append(f"{site.name} (rank {site.alexa_rank})")
+
+    assert missing_category == [], (
+        f"{len(missing_category)} top-{TOP_SITES_ALEXA_RANK_LIMIT} sites have no category tag: "
+        + ", ".join(missing_category[:20])
+    )
+
+
+@pytest.mark.slow
+def test_no_unused_tags_in_registry(default_db):
+    """Every tag in the registry should be used by at least one site."""
+    all_used_tags = set()
+    for site in default_db.sites:
+        for tag in site.tags:
+            if not is_country_tag(tag):
+                all_used_tags.add(tag)
+
+    registered_tags = set(default_db._tags)
+    unused = registered_tags - all_used_tags
+
+    assert unused == set(), f"Tags registered but not used by any site: {unused}"
+
+
+@pytest.mark.slow
+def test_social_networks_have_social_tag(default_db):
+    """Known social network domains must have the 'social' tag."""
+    from urllib.parse import urlparse
+
+    missing_social = []
+    for site in default_db.sites:
+        url = site.url_main or ""
+        try:
+            hostname = urlparse(url).hostname or ""
+        except Exception:
+            continue
+        for domain in KNOWN_SOCIAL_DOMAINS:
+            if hostname == domain or hostname.endswith("." + domain):
+                if "social" not in site.tags:
+                    missing_social.append(f"{site.name} ({domain})")
+                break
+
+    assert missing_social == [], (
+        f"{len(missing_social)} known social networks missing 'social' tag: "
+        + ", ".join(missing_social)
+    )