docs: declare where the data comes from, and under what terms

The module's own Apache-2.0 licence covers its code and says nothing
about the material it fetches. STORE.yaml now carries a data_source
block (publisher, url, terms, required attribution, and bundled:
false), and MODULE.md/MODULE.de.md explain it in both languages,
including the sentence that the retrieved text does not replace the
official version.

Enforced platform-side by data_source_gap in chain_hub::store_index;
the four rules are written up in docs/architecture/store-format.md of
the platform repo.

Signed-off-by: flemming-it <sf@flemming.it>

MODULE.de.md

@@ -41,6 +41,22 @@ Ausgaben: `formex` (Bytes, `application/xml`) und `meta` (JSON mit
 `celex`, `language`, `url`, `source_sha256`, `byte_len` sowie
 `consolidation_date` bei konsolidierten CELEX-Nummern).
 
+## Datenquelle
+
+EUR-Lex / CELLAR (Publications Office of the EU)
+
+Namensnennung: `Quelle: EUR-Lex, © Europäische Union, 1998-2026`
+
+Die Weiterverwendung der EUR-Lex-Dokumente ist nach dem Beschluss
+2011/833/EU der Kommission erlaubt, kommerziell wie nicht-kommerziell;
+redaktionelle Inhalte stehen unter CC BY 4.0. Bedingung ist die
+Quellenangabe. Einzelne Dokumente können abweichende Bedingungen tragen
+(etwa die International Accounting Standards); das steht dann im
+Amtsblatt beim jeweiligen Dokument.
+
+**Die zurückgegebene Fassung ersetzt nicht die amtliche Verkündung im
+Amtsblatt.**
+
 ## Lizenz
 
 Apache-2.0 — ein Ch∆In-Plattform-Modul (Flemming.AI).

MODULE.md

@@ -41,6 +41,21 @@ Outputs: `formex` (bytes, `application/xml`) and `meta` (JSON with
 `celex`, `language`, `url`, `source_sha256`, `byte_len`, and
 `consolidation_date` for consolidated CELEX numbers).
 
+## Data source
+
+EUR-Lex / CELLAR (Publications Office of the EU)
+
+Attribution: `Quelle: EUR-Lex, © Europäische Union, 1998-2026`
+
+Reuse of EUR-Lex documents is permitted under Commission Decision
+2011/833/EU, commercially and non-commercially; editorial content is
+CC BY 4.0. The condition is the attribution. Individual documents may
+carry different terms (the International Accounting Standards, for one);
+where they do, the Official Journal says so at the document.
+
+**The returned text does not replace the official publication in the
+Official Journal.**
+
 ## License
 
 Apache-2.0 — a Ch∆In platform module (Flemming.AI).

STORE.yaml

@@ -7,6 +7,17 @@ author:
 
 license: Apache-2.0
 
+# Where the data comes from, and under what terms. The `license`
+# above covers this module's code; this block covers the material
+# the module reaches. See docs/architecture/store-format.md.
+data_source:
+  name: "EUR-Lex / CELLAR (Publications Office of the EU)"
+  url: https://eur-lex.europa.eu/
+  license: "Wiederverwendung nach Beschluss 2011/833/EU; redaktionelle Inhalte CC BY 4.0"
+  attribution: "Quelle: EUR-Lex, © Europäische Union, 1998-2026"
+  # Never true: the module fetches at runtime and ships no corpus.
+  bundled: false
+
 tagline:
   en: "Fetch EU legal acts from EUR-Lex by CELEX"
   de: "EU-Rechtsakte per CELEX von EUR-Lex holen"