feat(ai-sdk): ePrivacy/cookie topic — §25 TDDDG co-primary for cookie questions

The TDDDG (ex-TTDSG) pilot revealed §25 TDDDG (terminal-equipment / cookie consent)
ranked #3 on a cookie query — the subsidiarity rule demoted it as DE law subsidiary
to the DSGVO, but TDDDG is lex specialis (ePrivacy) for cookies.

Topic-based fix (NOT blanket TDDDG > DSGVO):
- cookie/ePrivacy topic (cookie/endeinrichtung/endgeraet/tracking -> §25 TDDDG) so it is
  co-primary (topic-matched -> topicGain, no subsidiarity demote).
- TDDDG/TTDSG added to the data_protection domain (chunkDomain recognition).
- cookie-specific keywords (NOT bare 'Einwilligung') so a general consent question still
  resolves to Art. 7 DSGVO.

Acceptance on the DSGVO+BDSG+TDDDG build: cookie -> §25 TDDDG top-1; Rechtsgrundlage -> DSGVO;
DSB -> Art.37+§38 BDSG (not TDDDG); degraded=0, must_not=0. go build/vet/test green; 2 new table tests.

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

ai-compliance-sdk/internal/ucca/authority_rerank_test.go

@@ -123,6 +123,28 @@ func TestRerankByAuthority_Acceptance(t *testing.T) {
 		}
 	})
 
+	t.Run("ePrivacy: a cookie query lifts §25 TDDDG above DSGVO consent (lex specialis topic)", func(t *testing.T) {
+		in := []LegalSearchResult{
+			bindingRes("Art. 7 DSGVO", "DSGVO", "EU", 0.70), // higher semantic
+			bindingRes("§ 25 TDDDG", "TDDDG", "DE", 0.66),
+		}
+		out := rerankByAuthority("Wann ist eine Einwilligung fuer das Speichern von Cookies auf Endgeraeten erforderlich?", in)
+		if out[0].RegulationShort != "TDDDG" {
+			t.Fatalf("§25 TDDDG must win a cookie question (lex specialis topic), got %q", out[0].ArticleLabel)
+		}
+	})
+
+	t.Run("a general consent question still resolves to DSGVO, not §25 TDDDG", func(t *testing.T) {
+		in := []LegalSearchResult{
+			bindingRes("§ 25 TDDDG", "TDDDG", "DE", 0.70), // higher semantic but no cookie topic
+			bindingRes("Art. 7 DSGVO", "DSGVO", "EU", 0.66),
+		}
+		out := rerankByAuthority("Welche Anforderungen gelten an eine wirksame Einwilligung?", in)
+		if out[0].RegulationShort != "DSGVO" {
+			t.Fatalf("a general consent question must resolve to DSGVO (TDDDG demoted), got %q", out[0].ArticleLabel)
+		}
+	})
+
 	t.Run("co-primary dp_01: BDSG §38 stays top on a DSB question (national special rule)", func(t *testing.T) {
 		in := []LegalSearchResult{
 			bindingRes("§ 38 BDSG", "BDSG", "DE", 0.66),