fix: use configured endSymbols in injected prompt and exempt gateway keywords

- buildEndMarkerInstruction() replaces hardcoded END_MARKER_INSTRUCTION,
  dynamically using the resolved policy's endSymbols
- Instruction now explicitly exempts gateway keywords (NO_REPLY, HEARTBEAT_OK)
  from requiring end symbols
- Export resolvePolicy from rules.ts for reuse in before_prompt_build hook

plugin/index.ts

@@ -1,7 +1,7 @@
 import fs from "node:fs";
 import path from "node:path";
 import type { OpenClawPluginApi } from "openclaw/plugin-sdk";
-import { evaluateDecision, type ChannelPolicy, type Decision, type WhisperGateConfig } from "./rules.js";
+import { evaluateDecision, resolvePolicy, type ChannelPolicy, type Decision, type WhisperGateConfig } from "./rules.js";
 
 type DiscordControlAction = "channel-private-create" | "channel-private-update" | "member-list";
 
@@ -24,7 +24,10 @@ type DebugConfig = {
 const sessionDecision = new Map<string, DecisionRecord>();
 const MAX_SESSION_DECISIONS = 2000;
 const DECISION_TTL_MS = 5 * 60 * 1000;
-const END_MARKER_INSTRUCTION = "你的这次发言必须以🔚作为结尾。";
+function buildEndMarkerInstruction(endSymbols: string[]): string {
+  const symbols = endSymbols.length > 0 ? endSymbols.join("") : "🔚";
+  return `你的这次发言必须以${symbols}作为结尾。除非你的回复是 gateway 关键词（如 NO_REPLY、HEARTBEAT_OK），这些关键词不要加${symbols}。`;
+}
 
 const policyState: PolicyState = {
   filePath: "",
@@ -505,8 +508,14 @@ export default {
         return;
       }
 
+      // Resolve end symbols from config/policy for dynamic instruction
+      const prompt = ((event as Record<string, unknown>).prompt as string) || "";
+      const derived = deriveDecisionInputFromPrompt(prompt, ctx.messageProvider);
+      const policy = resolvePolicy(live, derived.channelId, policyState.channelPolicies);
+      const instruction = buildEndMarkerInstruction(policy.endSymbols);
+
       api.logger.info(`whispergate: prepend end marker instruction for session=${key}, reason=${rec.decision.reason}`);
-      return { prependContext: END_MARKER_INSTRUCTION };
+      return { prependContext: instruction };
     });
   },
 };

plugin/rules.ts

@@ -46,7 +46,7 @@ function getLastChar(input: string): string {
   return t.length ? t[t.length - 1] : "";
 }
 
-function resolvePolicy(config: WhisperGateConfig, channelId?: string, channelPolicies?: Record<string, ChannelPolicy>) {
+export function resolvePolicy(config: WhisperGateConfig, channelId?: string, channelPolicies?: Record<string, ChannelPolicy>) {
   const globalMode = config.listMode || "human-list";
   const globalHuman = config.humanList || config.bypassUserIds || [];
   const globalAgent = config.agentList || [];