fix(external_reputation): generische Plattform-Domains (t.me, twitter.com, ...) ignorieren

False positive bei sync_eu_disinfo: t.me wurde als Quelle markiert, weil
EUvsDisinfo anonyme Telegram-Posts unter der Plattform-Domain aggregiert.
Eine Allowlist von Plattform-Domains schliesst diese Falle aus.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/services/external_reputation.py

@@ -29,6 +29,20 @@ EU_DISINFO_CSV_URL = "https://zenodo.org/records/10514307/files/euvsdisinfo_base
 
 HTTP_TIMEOUT = httpx.Timeout(60.0, connect=10.0)
 
+# Generische Plattform-Domains, die NICHT als Quelle markiert werden duerfen
+# (EUvsDisinfo aggregiert anonyme Telegram-/Twitter-Posts unter Plattform-Domains).
+PLATFORM_DOMAINS = {
+    "t.me", "telegram.me", "telegram.org",
+    "twitter.com", "x.com", "mobile.twitter.com",
+    "youtube.com", "youtu.be", "m.youtube.com",
+    "facebook.com", "fb.com", "m.facebook.com",
+    "instagram.com", "tiktok.com", "vk.com", "ok.ru",
+    "rumble.com", "bitchute.com", "odysee.com",
+    "reddit.com", "old.reddit.com",
+    "wordpress.com", "blogspot.com", "medium.com",
+    "substack.com", "wixsite.com",
+}
+
 # Reliability-Skala in Stufenfolge (schlecht -> gut)
 RELIABILITY_ORDER = ["sehr_niedrig", "niedrig", "gemischt", "hoch", "sehr_hoch"]
 
@@ -84,7 +98,7 @@ async def sync_ifcn_signatories(db: aiosqlite.Connection) -> dict:
     unmatched_ids: list[int] = []
     for s in sources:
         nd = _normalize_domain(s["domain"])
-        if nd and nd in domains:
+        if nd and nd not in PLATFORM_DOMAINS and nd in domains:
             matched_ids.append(s["id"])
         else:
             unmatched_ids.append(s["id"])
@@ -151,7 +165,7 @@ async def sync_eu_disinfo(db: aiosqlite.Connection) -> dict:
     matched = 0
     for s in sources:
         nd = _normalize_domain(s["domain"])
-        if nd and nd in counts:
+        if nd and nd not in PLATFORM_DOMAINS and nd in counts:
             await db.execute(
                 """UPDATE sources SET
                     eu_disinfo_listed = 1,