chore: add gitleaks allowlist for upstream public client config (not secrets)

.gitleaks.toml

@@ -0,0 +1,19 @@
+# Sulkta gitleaks allowlist for this repo (a fork of vector-im/element-x-android).
+# These paths hold UPSTREAM Element X public client configuration — Firebase
+# google-services.json (client API keys, public-by-design, restricted by app
+# signing), PostHog / MapTiler / Localazy client keys, and login default
+# endpoints — all present in the upstream public repo. NOT Sulkta secrets.
+[extend]
+useDefault = true
+
+[allowlist]
+description = "Upstream Element X public client config (not secrets)"
+paths = [
+  '''google-services\.json$''',
+  '''localazy\.json$''',
+  '''tools/localazy/''',
+  '''features/location/''',
+  '''docs/maps\.md$''',
+  '''ElementClassicConnection\.kt$''',
+  '''services/analyticsproviders/posthog/''',
+]