feat(cookie): präfix-bewusster Library-Match (Runtime-Suffixe)

load_big_library matchte nur EXAKT → nur ~27% der BMW-Cookies trafen die
Open-Cookie-DB, weil Per-Instanz-Suffixe abweichen (_ga_GTM-XYZ, AMCVS_###@
AdobeOrg, _pk_id.5.7d8). Jetzt: Library einmal laden, Namen entwildcarden,
über _candidate_keys (exact + Präfix an Trennzeichen, Mindestlänge 3 gegen
Über-Match) matchen. Reuse der bewährten _strip_wildcards-Logik.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend-compliance/compliance/services/cookie_library_check.py

@@ -46,23 +46,70 @@ _CONTROL_MAP = {
 _HINWEIS_TYPES = {"third_country", "eu_alternative"}
 
 
+# Trennzeichen, an denen ein Runtime-Suffix abgeschnitten werden darf
+# (z.B. '_ga_GTM-XYZ' → '_ga', 'AMCVS_1234@AdobeOrg' → 'AMCVS').
+_SEP_RE = re.compile(r"[_\-.:$%@\[]")
+
+
+def _candidate_keys(name: str) -> list[str]:
+    """Library-Match-Kandidaten: voller (entwildcardeter) Name + Präfixe an
+    Trennzeichen. Fängt Per-Instanz-Suffixe (GTM-Container, @AdobeOrg, Hash-IDs),
+    ohne kurze generische Namen zu über-matchen (Mindestlänge 3)."""
+    from compliance.services.cookie_library_lookup import _strip_wildcards
+    base = _strip_wildcards(name)
+    keys: list[str] = []
+    if base:
+        keys.append(base)
+    cur = base
+    while True:
+        seps = list(_SEP_RE.finditer(cur))
+        if not seps:
+            break
+        cur = cur[:seps[-1].start()].rstrip("_-.:$%@")
+        if len(cur) >= 3 and cur not in keys:
+            keys.append(cur)
+        else:
+            break
+    return keys
+
+
+def _match_lib(name: str, lib_bases: dict) -> dict | None:
+    """Erster Treffer eines Kandidaten-Schlüssels in der (entwildcardeten)
+    Library-Basis-Map. Pure + testbar."""
+    for k in _candidate_keys(name):
+        if len(k) >= 3 and k in lib_bases:
+            return lib_bases[k]
+    return None
+
+
 def load_big_library(db, names: list[str]) -> dict:
-    """Batch-Lookup der grossen Open-Cookie-Database (compliance.cookie_library,
-    ~2287 Cookies) fuer die gegebenen Namen. Breite Abdeckung: Kategorie,
-    Retention, Vendor."""
-    uniq = sorted({(n or "").lower() for n in names if n})
+    """Präfix-bewusster Lookup gegen die Open-Cookie-Database
+    (compliance.cookie_library, ~2287). Lädt die Library einmal, entwildcardet
+    die Namen zu Basen und matcht jeden Cookie über _candidate_keys (exact +
+    Runtime-Suffix-Präfix). Schlüssel = ORIGINAL-Cookiename (lower) → Library-Row,
+    damit der Aufrufer wie gewohnt big_lib.get(name.lower()) nutzen kann."""
+    from compliance.services.cookie_library_lookup import _strip_wildcards
+    uniq = {(n or "").lower() for n in names if n}
     if not uniq:
         return {}
     rows = db.execute(
         text(
             "SELECT lower(cookie_name) AS n, actual_category, "
             "typical_max_age_seconds, vendor_name, purpose_de, purpose_en, "
-            "is_pii FROM compliance.cookie_library "
-            "WHERE lower(cookie_name) = ANY(:names)"
-        ),
-        {"names": uniq},
+            "is_pii FROM compliance.cookie_library"
+        )
     ).mappings().fetchall()
-    return {r["n"]: dict(r) for r in rows}
+    lib_bases: dict[str, dict] = {}
+    for r in rows:
+        base = _strip_wildcards(r["n"])
+        if base and base not in lib_bases:
+            lib_bases[base] = dict(r)
+    out: dict[str, dict] = {}
+    for low in uniq:
+        hit = _match_lib(low, lib_bases)
+        if hit:
+            out[low] = hit
+    return out
 
 _NECESSARY_CATS = {
     "necessary", "notwendig", "essential", "essenziell",

backend-compliance/compliance/tests/test_cookie_library_check.py

@@ -2,7 +2,27 @@
 
 from __future__ import annotations
 
-from compliance.services.cookie_library_check import analyze_cookies
+from compliance.services.cookie_library_check import (
+    _candidate_keys,
+    _match_lib,
+    analyze_cookies,
+)
+
+
+def test_candidate_keys_strips_runtime_suffix():
+    assert "_ga" in _candidate_keys("_ga_GTM-ABC123")
+    assert "amcvs" in _candidate_keys("AMCVS_1234@AdobeOrg")
+    assert "_pk_id" in _candidate_keys("_pk_id.5.7d8f")
+
+
+def test_match_lib_prefix_and_exact():
+    lib = {"_ga": {"actual_category": "statistics"},
+           "phpsessid": {"actual_category": "essential"}}
+    assert _match_lib("_ga_GTM-XYZ", lib)["actual_category"] == "statistics"
+    assert _match_lib("PHPSESSID".lower(), lib)["actual_category"] == "essential"
+    assert _match_lib("totally_unknown_xyz", lib) is None
+    # kurze generische Basis darf NICHT über-matchen
+    assert _match_lib("id_charger", {"id": {"x": 1}}) is None
 
 
 def test_tracker_declared_necessary_is_high_finding():