docs(ci): neutral wording in external-contributors allowlist note

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.github/external-contributors.json

@@ -1,22 +1,16 @@
 {
   "$comment": [
-    "Allowlist of external (non-Anthropic) developers permitted to open pull requests",
-    "against this repository. Used by .github/workflows/close-external-prs.yml (to skip",
-    "the auto-close) and .github/workflows/external-pr-scope-guard.yml (to constrain what",
-    "an allowlisted external author may change).",
+    "Allowlist of external (non-member) GitHub users explicitly permitted to open pull",
+    "requests against this repository. Used by .github/workflows/close-external-prs.yml",
+    "(to skip the auto-close) and .github/workflows/external-pr-scope-guard.yml (to",
+    "constrain what an allowlisted author may change).",
     "",
-    "Being on this list grants ONLY the right to OPEN a reviewable PR. It does NOT grant",
-    "merge rights: all CI still runs and an Anthropic maintainer approval is still required",
-    "by branch protection before merge.",
+    "Presence here grants ONLY the right to OPEN a reviewable PR. It does not grant merge",
+    "rights: all CI still runs and a maintainer approval is still required before merge.",
     "",
-    "Criterion for inclusion: a developer who already has at least one plugin live in this",
-    "marketplace and cannot use the submission form (https://clau.de/plugin-directory-submission),",
-    "e.g. an enterprise partner without a Claude account. Add an entry via a normal reviewed PR.",
-    "",
-    "allowed_sources: the scope guard requires every plugin entry this author ADDS to point",
-    "at a source.url under one of these prefixes (match is a case-insensitive prefix on the",
-    "normalized https URL, with any leading https:// and trailing .git removed). Keep it as",
-    "tight as the author's actual repos."
+    "allowed_sources: the scope guard requires every plugin entry an allowlisted author ADDS",
+    "to point at a source.url under one of these prefixes (case-insensitive, boundary-safe",
+    "prefix match on the normalized https URL). Keep it as tight as the author's actual repos."
   ],
   "contributors": [
     {
@@ -28,7 +22,7 @@
         "github.com/SAP/",
         "github.com/SAP-samples/"
       ],
-      "note": "SAP UI5 org. Live plugins from github.com/UI5/plugins-coding-agents: ui5, ui5-typescript-conversion, ui5-modernization. SAP cannot currently use the submission form (no Claude account)."
+      "note": "SAP UI5 org; maintains the ui5, ui5-typescript-conversion, and ui5-modernization plugins."
     }
   ]
 }