fix: keep async music delivery agent-mediated (#75335)

Keep async music generation completions on the requester-session wake path even when direct-send completion is enabled.

Also aligns config help, generated schema text, public docs, and the changelog so tools.media.asyncCompletion.directSend no longer claims to direct-send music completions.

Verification:
- pnpm test src/agents/tools/music-generate-background.test.ts src/agents/tools/video-generate-background.test.ts
- pnpm exec oxfmt --check --threads=1 src/agents/tools/media-generate-background-shared.ts src/agents/tools/music-generate-background.ts src/agents/tools/music-generate-background.test.ts src/config/schema.help.ts src/config/types.tools.ts docs/automation/tasks.md docs/gateway/config-tools.md CHANGELOG.md
- pnpm config:schema:check
- pnpm config:docs:check
- pnpm check:changelog-attributions
- git diff --check
- OPENCLAW_TESTBOX=1 pnpm check:changed

docs/.generated/config-baseline.sha256

@@ -1,4 +1,4 @@
-f2f5dc47ab9572fa5f80eb01b5a176edb04ca91c7a25bea3b9ea8e19dd21904b  config-baseline.json
-d81f9cadab9762a4b542795ed1f01f27e374f9811cf176f08cbbb7a20b044c15  config-baseline.core.json
+a69e6b650513c2a697ee51087928bf78f63ba998c7c60f8cca61dd65a0184fd0  config-baseline.json
+0a259216178a582c567d1fa48c5236bff4bbd27c3e6af838ffcd042459ffce3c  config-baseline.core.json
 92712871defa92eeda8161b516db85574681f2b70678b940508a808b987aeae2  config-baseline.channel.json
 6005cf9f6e8c9f25ef97207b5eee29ae0e506cf910cdeca77fc9894ad1755b1f  config-baseline.plugin.json

docs/automation/tasks.md

@@ -96,13 +96,13 @@ Not every agent run creates a task. Heartbeat turns and normal interactive chat
 | Subagent orchestration | `subagent`   | Spawning a subagent via `sessions_spawn`               | `done_only`           |
 | Cron jobs (all types)  | `cron`       | Every cron execution (main-session and isolated)       | `silent`              |
 | CLI operations         | `cli`        | `openclaw agent` commands that run through the gateway | `silent`              |
-| Agent media jobs       | `cli`        | Session-backed `video_generate` runs                   | `silent`              |
+| Agent media jobs       | `cli`        | Session-backed `music_generate`/`video_generate` runs  | `silent`              |
 
 <AccordionGroup>
   <Accordion title="Notify defaults for cron and media">
     Main-session cron tasks use `silent` notify policy by default — they create records for tracking but do not generate notifications. Isolated cron tasks also default to `silent` but are more visible because they run in their own session.
 
-    Session-backed `video_generate` runs also use `silent` notify policy. They still create task records, but completion is handed back to the original agent session as an internal wake so the agent can write the follow-up message and attach the finished video itself. If you opt into `tools.media.asyncCompletion.directSend`, async `music_generate` and `video_generate` completions try direct channel delivery first before falling back to the requester-session wake path.
+    Session-backed `music_generate` and `video_generate` runs also use `silent` notify policy. They still create task records, but completion is handed back to the original agent session as an internal wake so the agent can write the follow-up message and attach the finished media itself. If you opt into `tools.media.asyncCompletion.directSend`, async `video_generate` completions can try direct channel delivery first; async `music_generate` completions stay on the requester-session wake path.
 
   </Accordion>
   <Accordion title="Concurrent video_generate guardrail">

docs/gateway/config-tools.md

@@ -201,7 +201,7 @@ Configures inbound media understanding (image/audio/video):
     media: {
       concurrency: 2,
       asyncCompletion: {
-        directSend: false, // opt-in: send finished async music/video directly to the channel
+        directSend: false, // opt-in: send finished async video directly to the channel
       },
       audio: {
         enabled: true,
@@ -254,7 +254,7 @@ Configures inbound media understanding (image/audio/video):
 
     **Async completion fields:**
 
-    - `asyncCompletion.directSend`: when `true`, completed async `music_generate` and `video_generate` tasks try direct channel delivery first. Default: `false` (legacy requester-session wake/model-delivery path).
+    - `asyncCompletion.directSend`: when `true`, completed async media tasks that support direct completion delivery try direct channel delivery first. Default: `false` (requester-session wake/model-delivery path). Today this applies to async `video_generate`; async `music_generate` completions stay requester-session mediated even when this is enabled.
 
   </Accordion>
 </AccordionGroup>