feat(mosaic): complete credential lifecycle and fail closed

packages/mosaic/framework/tools/git/git-credential-mosaic

@@ -45,8 +45,23 @@ if [ -n "$ident" ]; then
       echo "password=$(cat "$idtok")"
       exit 0
     fi
+    if [ -n "${MOSAIC_AGENT_NAME:-}" ]; then
+      echo "quit=true"
+      printf 'MOSAIC_CREDENTIAL_REFUSAL outcome=refused reason=no-token-for-identity identity=%s host=%s shared_path_entered=false source=git-credential-mosaic path=%s\n' \
+        "$ident" "$host" "$idtok" >&2
+      exit 1
+    fi
   fi
 fi
+if [ -n "${MOSAIC_AGENT_NAME:-}" ] && [ -z "$ident" ]; then
+  case "$host" in
+    git.uscllc.com|git.mosaicstack.dev)
+      echo "quit=true"
+      printf 'MOSAIC_CREDENTIAL_REFUSAL outcome=refused reason=identity-required identity=<unset> host=%s shared_path_entered=false source=git-credential-mosaic\n' "$host" >&2
+      exit 1
+      ;;
+  esac
+fi
 case "$host" in
   git.uscllc.com)      svc=gitea-usc;;
   git.mosaicstack.dev) svc=gitea-mosaicstack;;