fix: identity-check name resolutions across the pasted closure; exclude the catalog from i18n pairing

Review findings on the config catalog:

The transitive-paste closure deduplicated by bare name, so two DIFFERENT
package-local declarations sharing a name would silently collapse to the
first one pasted — and a reference satisfied by the wrong declaration is a
wrong catalog, not just a thin one. Every resolution is now identity-checked
by source pointer: reaching the same declaration again is benign, while a
name that resolves to two distinct declarations, to conflicting imports, or
to a declaration in one file and an import in another is a violation — a
verbatim fence has a single flat namespace, so the fix is a rename at the
source. A spec case pins the two-declarations collision.

docs/config-catalog.md also joins the translation-pairing exclusions: it is
a generated English-only doc, and without the entry the gate would accept a
hand-added .zh.md twin it must reject.

scripts/translation-pairing.manifest.json

@@ -9,6 +9,7 @@
   "excluded": [
     "docs/AGENTS.md",
     "docs/module-graph.md",
+    "docs/config-catalog.md",
     "docs/cordis-catalog/",
     "docs/tool-catalog/",
     "docs/persistence-catalog/",