feat: per-channel responsePrefix override (#9001)

* feat: per-channel responsePrefix override

Add responsePrefix field to all channel config types and Zod schemas,
enabling per-channel and per-account outbound response prefix overrides.

Resolution cascade (most specific wins):
  L1: channels.<ch>.accounts.<id>.responsePrefix
  L2: channels.<ch>.responsePrefix
  L3: (reserved for channels.defaults)
  L4: messages.responsePrefix (existing global)

Semantics:
  - undefined -> inherit from parent level
  - empty string -> explicitly no prefix (stops cascade)
  - "auto" -> derive [identity.name] from routed agent

Changes:
  - Core logic: resolveResponsePrefix() in identity.ts accepts
    optional channel/accountId and walks the cascade
  - resolveEffectiveMessagesConfig() passes channel context through
  - Types: responsePrefix added to WhatsApp, Telegram, Discord, Slack,
    Signal, iMessage, Google Chat, MS Teams, Feishu, BlueBubbles configs
  - Zod schemas: responsePrefix added for config validation
  - All channel handlers wired: telegram, discord, slack, signal,
    imessage, line, heartbeat runner, route-reply, native commands
  - 23 new tests covering backward compat, channel/account levels,
    full cascade, auto keyword, empty string stops, unknown fallthrough

Fully backward compatible - no existing config is affected.
Fixes #8857

* fix: address CI lint + review feedback

- Replace Record<string, any> with proper typed helpers (no-explicit-any)
- Add curly braces to single-line if returns (eslint curly)
- Fix JSDoc: 'Per-channel' → 'channel/account' on shared config types
- Extract getChannelConfig() helper for type-safe dynamic key access

* fix: finish responsePrefix overrides (#9001) (thanks @mudrii)

* fix: normalize prefix wiring and types (#9001) (thanks @mudrii)

---------

Co-authored-by: Gustavo Madeira Santana <gumadeiras@gmail.com>

src/telegram/bot-native-commands.ts

@@ -10,7 +10,6 @@ import type {
 } from "../config/types.js";
 import type { RuntimeEnv } from "../runtime.js";
 import type { TelegramContext } from "./bot/types.js";
-import { resolveEffectiveMessagesConfig } from "../agents/identity.js";
 import { resolveChunkMode } from "../auto-reply/chunk.js";
 import {
   buildCommandTextFromArgs,
@@ -24,6 +23,7 @@ import { finalizeInboundContext } from "../auto-reply/reply/inbound-context.js";
 import { dispatchReplyWithBufferedBlockDispatcher } from "../auto-reply/reply/provider-dispatcher.js";
 import { listSkillCommandsForAgents } from "../auto-reply/skill-commands.js";
 import { resolveCommandAuthorizedFromAuthorizers } from "../channels/command-gating.js";
+import { createReplyPrefixOptions } from "../channels/reply-prefix.js";
 import { resolveMarkdownTableMode } from "../config/markdown-tables.js";
 import { resolveTelegramCustomCommands } from "../config/telegram-custom-commands.js";
 import {
@@ -547,11 +547,18 @@ export const registerTelegramNativeCommands = ({
             skippedNonSilent: 0,
           };
 
+          const { onModelSelected, ...prefixOptions } = createReplyPrefixOptions({
+            cfg,
+            agentId: route.agentId,
+            channel: "telegram",
+            accountId: route.accountId,
+          });
+
           await dispatchReplyWithBufferedBlockDispatcher({
             ctx: ctxPayload,
             cfg,
             dispatcherOptions: {
-              responsePrefix: resolveEffectiveMessagesConfig(cfg, route.agentId).responsePrefix,
+              ...prefixOptions,
               deliver: async (payload, _info) => {
                 const result = await deliverReplies({
                   replies: [payload],
@@ -582,6 +589,7 @@ export const registerTelegramNativeCommands = ({
             replyOptions: {
               skillFilter,
               disableBlockStreaming,
+              onModelSelected,
             },
           });
           if (!deliveryState.delivered && deliveryState.skippedNonSilent > 0) {