refactor: unify dm policy store reads and reason codes

src/discord/monitor/native-command.ts

@@ -53,6 +53,7 @@ import {
 import { resolveAgentRoute } from "../../routing/resolve-route.js";
 import { resolveAgentIdFromSessionKey } from "../../routing/session-key.js";
 import { buildUntrustedChannelMetadata } from "../../security/channel-metadata.js";
+import { readStoreAllowFromForDmPolicy } from "../../security/dm-policy-shared.js";
 import { chunkItems } from "../../utils/chunk-items.js";
 import { withTimeout } from "../../utils/with-timeout.js";
 import { loadWebMedia } from "../../web/media.js";
@@ -1360,8 +1361,11 @@ async function dispatchDiscordCommandInteraction(params: {
       return;
     }
     if (dmPolicy !== "open") {
-      const storeAllowFrom =
-        dmPolicy === "allowlist" ? [] : await readChannelAllowFromStore("discord").catch(() => []);
+      const storeAllowFrom = await readStoreAllowFromForDmPolicy({
+        provider: "discord",
+        dmPolicy,
+        readStore: (provider) => readChannelAllowFromStore(provider),
+      });
       const effectiveAllowFrom = [
         ...(discordConfig?.allowFrom ?? discordConfig?.dm?.allowFrom ?? []),
         ...storeAllowFrom,