feat(hooks): add message:transcribed and message:preprocessed internal hooks

Adds two new internal hook events that fire after media/link processing:

- message:transcribed: fires when audio has been transcribed, providing
  the transcript text alongside the original body and media metadata.
  Useful for logging, analytics, or routing based on spoken content.

- message:preprocessed: fires for every message after all media + link
  understanding completes. Gives hooks access to the fully enriched body
  (transcripts, image descriptions, link summaries) before the agent sees it.

Both hooks are added in get-reply.ts, after applyMediaUnderstanding and
applyLinkUnderstanding. message:received and message:sent are already
in upstream (f07bb8e8) and are not duplicated here.

Typed contexts (MessageTranscribedHookContext, MessagePreprocessedHookContext)
and type guards (isMessageTranscribedEvent, isMessagePreprocessedEvent) added
to internal-hooks.ts alongside the existing received/sent types.

Test coverage in src/hooks/message-hooks.test.ts.

src/auto-reply/reply/get-reply.ts

@@ -9,6 +9,8 @@ import { resolveAgentTimeoutMs } from "../../agents/timeout.js";
 import { DEFAULT_AGENT_WORKSPACE_DIR, ensureAgentWorkspace } from "../../agents/workspace.js";
 import { resolveChannelModelOverride } from "../../channels/model-overrides.js";
 import { type OpenClawConfig, loadConfig } from "../../config/config.js";
+import { logVerbose } from "../../globals.js";
+import { createInternalHookEvent, triggerInternalHook } from "../../hooks/internal-hooks.js";
 import { applyLinkUnderstanding } from "../../link-understanding/apply.js";
 import { applyMediaUnderstanding } from "../../media-understanding/apply.js";
 import { defaultRuntime } from "../../runtime.js";
@@ -136,6 +138,73 @@ export async function getReplyFromConfig(
     });
   }
 
+  const channelId = (
+    finalized.OriginatingChannel ??
+    finalized.Surface ??
+    finalized.Provider ??
+    ""
+  ).toLowerCase();
+
+  // Trigger message:transcribed hook after media understanding completes
+  // Only fire if transcription actually occurred (skip in fast test mode or non-audio)
+  if (finalized.Transcript) {
+    void triggerInternalHook(
+      createInternalHookEvent("message", "transcribed", finalized.SessionKey ?? "", {
+        from: finalized.From,
+        to: finalized.To,
+        body: finalized.Body,
+        bodyForAgent: finalized.BodyForAgent,
+        transcript: finalized.Transcript,
+        timestamp: finalized.Timestamp,
+        channelId,
+        conversationId: finalized.OriginatingTo ?? finalized.To ?? finalized.From ?? undefined,
+        messageId: finalized.MessageSid,
+        senderId: finalized.SenderId,
+        senderName: finalized.SenderName,
+        senderUsername: finalized.SenderUsername,
+        provider: finalized.Provider,
+        surface: finalized.Surface,
+        mediaPath: finalized.MediaPath,
+        mediaType: finalized.MediaType,
+        cfg,
+      }),
+    ).catch((err) => {
+      logVerbose(`get-reply: message:transcribed internal hook failed: ${String(err)}`);
+    });
+  }
+
+  // Trigger message:preprocessed hook after all media + link understanding.
+  // Fires for every message, giving hooks access to the fully enriched body
+  // (transcripts, image descriptions, link summaries) before the agent sees it.
+  void triggerInternalHook(
+    createInternalHookEvent("message", "preprocessed", finalized.SessionKey ?? "", {
+      from: finalized.From,
+      to: finalized.To,
+      body: finalized.Body,
+      bodyForAgent: finalized.BodyForAgent,
+      transcript: finalized.Transcript,
+      timestamp: finalized.Timestamp,
+      channelId,
+      conversationId: finalized.OriginatingTo ?? finalized.To ?? finalized.From ?? undefined,
+      messageId: finalized.MessageSid,
+      senderId: finalized.SenderId,
+      senderName: finalized.SenderName,
+      senderUsername: finalized.SenderUsername,
+      provider: finalized.Provider,
+      surface: finalized.Surface,
+      mediaPath: finalized.MediaPath,
+      mediaType: finalized.MediaType,
+      isGroup: Boolean(finalized.GroupSubject || finalized.GroupChannel),
+      groupId:
+        finalized.From?.includes(":group:") || finalized.From?.includes(":channel:")
+          ? finalized.From
+          : undefined,
+      cfg,
+    }),
+  ).catch((err) => {
+    logVerbose(`get-reply: message:preprocessed internal hook failed: ${String(err)}`);
+  });
+
   const commandAuthorized = finalized.CommandAuthorized;
   resolveCommandAuthorization({
     ctx: finalized,