fix(channelbridge): IM 发送过滤 action/narration + <p>拆多气泡 + 0.5-2s 间隔

把回复转发给 IM 适配器(sendReply)时剥掉 <action>/<narration> 动作/内心独白(Web 端
才渲染灰斜体，IM 只能收纯文本)，并按 <p> 段落拆成多条气泡分别发送；多气泡发送间隔
随机 0.5~2s(仅 IM，Web 前端不延迟)。新增 sanitize.go stripNarration/splitBubbles/
bubbleGap + 测试。

frontend/web/src/admin/modules/channels/channelUtils.ts

@@ -0,0 +1,64 @@
+import type { AdminChannelRecord } from "../../../lib/types";
+import { PLATFORM_FIELDS } from "../channelFields";
+import type { ChannelConfigInitial } from "../channelConfigForm";
+
+/** Platform part of an adapter name ("kook:conf0" → "kook"). */
+export function platformOf(name: string): string {
+  return name.split(":")[0];
+}
+
+/** Adapter (platform:account) name for one account config. The bridge registers a
+ * channels.json account as "kook:conf0" (env single-account = bare platform), so a
+ * config id of "default"/"" maps to the bare platform name. */
+export function adapterNameOf(platform: string, accountId?: string): string {
+  const id = accountId?.trim();
+  return id && id !== "default" ? `${platform}:${id}` : platform;
+}
+
+/** Open-config target: the platform + the prefill bundle for its form. */
+export interface CfgTarget {
+  platform: string;
+  initial: ChannelConfigInitial;
+}
+
+/** Build the config-form prefill from a platform name and the channel records.
+ *  Do NOT put the masked placeholder into `token`: it would be written back as
+ *  the real bot_token (overwriting the stored secret with a demo string). Keep
+ *  token empty (save omits it → keeps the existing secret) and show a hint. */
+export function buildCfgTarget(name: string, records: AdminChannelRecord[]): CfgTarget {
+  const plat = platformOf(name);
+  const acct = records.find((c) => platformOf(c.name) === plat)?.accounts?.[0];
+  const acctCfg = acct?.config ?? {};
+  const hasToken = typeof acctCfg.bot_token === "string" && acctCfg.bot_token && !acctCfg.bot_token.includes("（已配置");
+  const platVals: Record<string, string> = {};
+  for (const f of PLATFORM_FIELDS[plat] ?? []) {
+    const v = acctCfg[f.key];
+    platVals[f.key] = v == null ? "" : String(v);
+  }
+  return {
+    platform: plat,
+    initial: {
+      accountId: acct?.id ?? "",
+      tokenHint: hasToken ? "已配置（仅掩码显示），留空则不改动；如需更换请重新输入。" : "",
+      baseURL: typeof acctCfg.base_url === "string" ? acctCfg.base_url : "",
+      platVals,
+      allowGroups: (acct?.allowGroups ?? []).join(","),
+      denyGroups: (acct?.denyGroups ?? []).join(","),
+      allowUsers: (acct?.allowUsers ?? []).join(","),
+      denyUsers: acct?.denyUsers ? (Array.isArray(acct.denyUsers) ? acct.denyUsers.join(",") : "") : "",
+      groupMsgPerMin: acctCfg.groupMsgPerMin == null ? "" : String(acctCfg.groupMsgPerMin),
+      msgPerMin: acctCfg.msgPerMin == null ? "" : String(acctCfg.msgPerMin),
+      maxMessages: acctCfg.maxMessages == null ? "" : String(acctCfg.maxMessages),
+    },
+  };
+}
+
+/** The set of platforms that have at least one configured account. */
+export function configuredPlatforms(records: AdminChannelRecord[]): AdminChannelRecord[] {
+  return records.filter((c) => (c.accounts?.length ?? 0) > 0);
+}
+
+/** Total configured accounts across all platforms. */
+export function configuredAccountCount(records: AdminChannelRecord[]): number {
+  return configuredPlatforms(records).reduce((n, c) => n + (c.accounts?.length ?? 0), 0);
+}