refactor: unify account-scoped dm security policy resolver

extensions/signal/src/channel.ts

@@ -1,4 +1,7 @@
-import { buildOpenGroupPolicyRestrictSendersWarning } from "openclaw/plugin-sdk";
+import {
+  buildAccountScopedDmSecurityPolicy,
+  buildOpenGroupPolicyRestrictSendersWarning,
+} from "openclaw/plugin-sdk";
 import {
   applyAccountNameToChannelSection,
   buildBaseAccountStatusSnapshot,
@@ -8,7 +11,6 @@ import {
   createDefaultChannelRuntimeState,
   DEFAULT_ACCOUNT_ID,
   deleteAccountFromConfigSection,
-  formatPairingApproveHint,
   getChatChannelMeta,
   listSignalAccountIds,
   looksLikeSignalTargetId,
@@ -155,19 +157,16 @@ export const signalPlugin: ChannelPlugin<ResolvedSignalAccount> = {
   },
   security: {
     resolveDmPolicy: ({ cfg, accountId, account }) => {
-      const resolvedAccountId = accountId ?? account.accountId ?? DEFAULT_ACCOUNT_ID;
-      const useAccountPath = Boolean(cfg.channels?.signal?.accounts?.[resolvedAccountId]);
-      const basePath = useAccountPath
-        ? `channels.signal.accounts.${resolvedAccountId}.`
-        : "channels.signal.";
-      return {
-        policy: account.config.dmPolicy ?? "pairing",
+      return buildAccountScopedDmSecurityPolicy({
+        cfg,
+        channelKey: "signal",
+        accountId,
+        fallbackAccountId: account.accountId ?? DEFAULT_ACCOUNT_ID,
+        policy: account.config.dmPolicy,
         allowFrom: account.config.allowFrom ?? [],
-        policyPath: `${basePath}dmPolicy`,
-        allowFromPath: basePath,
-        approveHint: formatPairingApproveHint("signal"),
+        policyPathSuffix: "dmPolicy",
         normalizeEntry: (raw) => normalizeE164(raw.replace(/^signal:/i, "").trim()),
-      };
+      });
     },
     collectWarnings: ({ account, cfg }) => {
       const defaultGroupPolicy = resolveDefaultGroupPolicy(cfg);